Publications
Filters
total: 273
Catalog Publications
Year 2017
-
Superconductivity in a new intermetallic structure type based on endohedral Ta@Ir7Ge4 clusters
PublicationWe report the observation of superconductivity at a temperature near 3.5 K for the previously unreported compound TaIr2Ge2. In addition to being a superconductor, this material displays a new crystal structure type that contains endohedral clusters, as determined by single-crystal x-ray diffraction structure refinement; the structure is more complex than those of the commonly observed tetragonal 122 intermetallic phases. Despite...
-
Superconductivity in the Nb-Ru-Ge σ phase
PublicationWe show that the previously unreported ternary σ-phase material Nb20.4Ru5.7Ge3.9 (Nb0.68Ru0.19Ge0.13) is a superconductor with a critical temperature of 2.2 K. Temperature-dependent magnetic susceptibility, resistance, and specific-heat measurements were used to characterize the superconducting transition. The Sommerfeld constant γ for Nb20.4Ru5.7Ge3.9 is 91 mJ mol f.u. −1K−2 (∼3 mJ mol atom−1 K−2) and the specific-heat anomaly at...
-
Synthesis and properties of AxV2Al20 (A = Th, U, Np, Pu) ternary actinide aluminides
PublicationPolycrystalline samples of AxV2Al20 (A = Ce, Th, U, Np, Pu; 0.7 ≤ x ≤ 1.0) actinide intermetallics were synthesized using the arc-melting method. Crystal structure studies were performed by means of powder x-ray diffraction and the Rietveld refinement method. All studied compounds crystallize in the CeCr2Al20-type structure (space group Fd-3m, no. 227) with the actinoid and Ce atom located in the oversized icosahedral cage formed...
-
Synthesis and properties of HoT2Al20 (T = Ti, V, Cr) intermetallic cage compounds
PublicationPolycrystalline samples of HoT2Al20 (T = Ti, V, Cr) intermetallics were synthesized using a step-wise arc-melting technique. All three compounds adopt the CeCr2Al20-type crystal structure with Ho atoms positioned inside oversized icosahedral cages formed by Al atoms. The structure of HoV2Al20 compound is reported. The materials properties were studied by means of electrical resistivity, magnetic susceptibility, and specific heat...
-
The effects of bifunctional linker and reflux time on the surface properties and photocatalytic activity of CdTe quantum dots decorated KTaO3 composite photocatalysts
PublicationNovel CdTe-KTaO3composite photocatalysts were successfully synthesized by using thioglycolic acid(TGA) or 3-mercaptopropionic acid (MPA) as linker molecules which facilitated attachment of CdTequantum dots to the surface of KTaO3nanocubes. The as-prepared photocatalysts were characterizedby UV–vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy...
-
The ILs-assisted electrochemical synthesis of TiO2 nanotubes: The effect of ionic liquids on morphology and photoactivity
PublicationFacile and environmentally benign one-step titanium anodization method for TiO2 nanotubes (NTs) formation in a presence of ionic liquids (ILs) was proposed. Influence of the IL structure and its content in ethylene glycol electrolyte on morphology, surface properties and photoactivity of the TiO2 NTs was investigated. Possible interactions between IL and TiO2 NTs as well as the mechanism of NTs formation during anodic oxidation...
-
The LaPdIn 4 indide and elementary properties of the LaTIn 4 ( T = Ni, Pd, Pt) materials family
PublicationThe indium-rich intermetallic compound LaPdIn4 is reported, prepared by arc-melting and annealing at 600 C. Single crystal X-ray diffraction found the material to be orthorhombic, space group Cmcm (No. 63), with lattice parameters a ¼ 4.5462(3) Å, b ¼ 16.9208(10) Å, and c ¼ 7.3100(5) Å. This previously unreported indide is isostructural with LaNiIn4 and LaPtIn4. It is demonstrated that all three compounds in the LaTIn4 (T ¼ Ni,...
-
TiO2 /SrTiO3 and SrTiO3 microspheres decorated with Rh, Ru or Pt nanoparticles: Highly UV–vis responsible photoactivity and mechanism
PublicationA series of TiO2/SrTiO3 and SrTiO3 microspheres decorated by Rh, Ru or Pt NPs were prepared by facile hydrothermal method. The as-prepared samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) with energy-dispersive Xray (EDX) spectroscopy, scanning electron microscopy (SEM), photoluminescence spectrometry (PL), Fourier transform infrared (FT-IR) and...
-
Various types of semiconductor photocatalysts modified by CdTe QDs and Pt NPs for toluene photooxidation in the gas phase under visible light
PublicationA novel synthesis process was used to prepare TiO2 microspheres, TiO2 P-25, SrTiO3 and KTaO3 decorated by CdTe QDs and/or Pt NPs. The effect of semiconductor matrix, presence of CdTe QDs and/or Pt NPs on the semiconductor surface as well as deposition technique of Pt NPs (photodeposition or radiolysis) on the photocatalytic activity were investigated. The as-prepared samples were characterized by X-ray powder diffractometry (XRD),...
Year 2016
-
Crystal structure and physical properties of new Ca2TGe3 (T = Pd and Pt) germanides
PublicationThe crystallographic, electronic transport and thermal properties of Ca2PdGe3 and Ca2PtGe3 are reported. The compounds crystalize in an ordered variant of the AlB2 crystal structure, in space group P6/mmm, with the lattice parameters a = 8.4876(4) Å/8.4503(5) Å and c = 4.1911(3) Å/4.2302(3) Å for Ca2PdGe3 and Ca2PtGe3, respectively. The resistivity data exhibit metallic behavior with residual-resistivity-ratios (RRR) of 13 for...
-
Effect of electron count and chemical complexity in the Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor
PublicationHigh-entropy alloys are made from random mixtures of principal elements on simple lattices, stabilized by a high mixing entropy. The recently discovered body-centered cubic (BCC) Ta-Nb-Hf-Zr-Ti high-entropy alloy superconductor appears to display properties of both simple crystalline intermetallics and amorphous materials; e.g., it has a well-defined superconducting transition along with an exceptional robustness against disorder....
-
Field-induced suppression of charge density wave in GdNiC2
PublicationWe report the specific heat, magnetic, magnetotransport, and galvanomagnetic properties of polycrystalline GdNiC 2 . In the intermediate temperature region above T N = 20 K, we observe large negative magnetoresistance due to Zeeman splitting of the electronic bands and partial destruction of a charge density wave ground state. Our magnetoresistance and Hall measurements show that at low temperatures a magnetic field-induced transformation from...
-
Heat capacities and thermodynamic properties of antimony substituted lanthanum orthoniobates
PublicationThe results of heat capacity measurements for the lanthanum orthoniobate substituted with 10, 20 and 30 mol% of antimony (LaNb0.9Sb0.1O4, LaNb0.8Sb0.2O4 and LaNb0.7Sb0.3O4) are presented and discussed. Temperature dependence of low temperature heat capacity was analyzed within the Debye and Einstein models. The Debye temperature decreased, whereas the Einstein temperature increased with antimony content. The decrease of the Debye...
-
Noble metal modified TiO2 microspheres: Surface properties and photocatalytic activity under UV-vis and visible light
PublicationComposite photocatalysts that consist of TiO2and noble metal nanostructures have been considered tobe the promising and pivotal material for accessible enhancement of the efficiency in the photocatalyticprocess carried out in the aqueous and gas phases. In this work we fabricated porous TiO2microspheresthrough a hydrothermal process followed by photochemical reduction of noble metal nanoparticles atthe TiO2surface. The morphology...
-
Photocatalytic activity of nitrogen doped TiO2 nanotubes prepared by anodic oxidation: The effect of applied voltage, anodization time and amount of nitrogen dopant
PublicationNitrogen doped TiO2 nanotube arrays were prepared by anodizing Ti foils in an organic electrolyte containing specified amounts of urea as nitrogen precursor. The photocatalytic activity of the samples was evaluated by analyzing the degradation kinetics of phenol in water. The influence of tubes’ length, tubes’ surface morphology and amount of nitrogen in the TiO2 lattice on hydroxyl radical formation efficiency, photocatalytic...
-
Physical properties and electronic structure of La3Co and La3Ni intermetallic superconductors
PublicationLa3Co and La3Ni are reported superconductors with transition temperatures of 4.5 and 6 K, respectively. Here, we reinvestigate the physical properties of these two intermetallic compounds with magnetic susceptibility χ, specific heat Cp and electrical resistivity ρ measurements down to 1.9 K. Although bulk superconductivity is confirmed in La3Co, as observed previously, only a trace of it is found in La3Ni, indicating that the...
-
Preparation, characterization and photocatalytic activity of TiO2 microspheres decorated by bimetallic nanoparticles
PublicationComposite photocatalysts that consist of TiO2and noble metal nanostructures have been considered tobe the promising and pivotal material for accessible enhancement of the efficiency in the photocatalyticprocess carried out in the aqueous and gas phases. In this work we fabricated porous TiO2microspheresthrough a hydrothermal process followed by photochemical reduction of noble metal nanoparticles atthe TiO2surface. The morphology...
-
Rattling-enhanced superconductivity in MV2Al20 (M = Sc, Lu, Y) intermetallic cage compounds
PublicationPolycrystalline samples of four intermetallic compounds: MV2Al20 (M=Sc, Y, La, and Lu) were synthesized using an arc-melting technique. The crystal structures were analyzed by means of powder x-ray diffraction and Rietveld analysis, and the physical properties were studied by means of heat capacity, electrical resistivity, and magnetic susceptibility measurements down to 0.4 K. For ScV2Al20, LuV2Al20, and YV2Al20, superconductivity...
-
Superconductivity and ferromagnetism in Pd doped Y9Co7
PublicationThe ferromagnetic superconductor Y9Co7 was chemically doped to yield the solid solution Y9Co7-xPdx for 0 < x < 0.4. The lattice parameter a does not depend on x, whereas c increases with increasing Pd content up to x ¼ 0.2, the palladium solubility limit. The transition from ferromagnetism (TC ¼ 4.25 K) to superconductivity (Tsc ¼ 2.4 K) was observed only for the parent Y9Co7 compound. For the lowest tested Pd doping level (x ¼...
-
Superconductivity and itinerant ferromagnetism of Y9Co7 probed by ac susceptibility
PublicationThe ac magnetic susceptibility of a single crystal sample of the compound Y9Co7 has been measured in applied dc fields ranging from 0–6.7 kOe by utilizing a tunnel diode resonator circuit. In agreement with previous measurements on this material, a superconducting transition has been observed to occur at TSC ≈ 2.5 K. A broad maximum has been observed in the zero field susceptibility measurements from 2.5 K < T < 8 K and its behavior...
-
Superconductivity in CaBi2
PublicationSuperconductivity is observed with critical temperature Tc = 2.0 K in self-flux-grown single crystals of CaBi2. This material adopts the ZrSi2 structure type with lattice parameters a = 4.696(1) Å, b = 17.081(2) Å and c = 4.611(1) Å. The crystals of CaBi2 were studied by means of magnetic susceptibility, specific heat and electrical resistivity measurements. The heat capacity jump at Tc is DC/gTc = 1.41, confirming bulk superconductivity;...
-
The effect of metal cluster deposition route on structure and photocatalytic activity of mono- and bimetallic nanoparticles supported on TiO2 by radiolytic method
PublicationTiO2 (P25) was modified with small and relatively monodisperse mono- and bimetallic clusters (Ag, Pd, Pt, Ag/Pd, Ag/Pt and Pd/Pt) induced by radiolysis to improve its photocatalytic activity. The as-prepared samples were characterized by X-ray fluorescence spectrometry (XRF), photoluminescence spectrometry (PL), diffuse reflectance spectroscopy (DRS), X-ray powder diffractometry (XRD), scanning transition electron microscopy (STEM)...
-
Tuning the ferromagnetic phase in the CDW compound SmNiC2 via chemical alloying
PublicationWe report a study on tuning the charge density wave (CDW) ferromagnet SmNiC2 to a weakly coupled superconductor by substituting La for Sm. X-ray diffraction measurements show that the doped compounds obey Vegard’s law, where La (Lu) alloying expands (shrinks) the lattice due to its larger (smaller) atomic size than Sm. In the series Sm1−xLaxNiC2, CDW transition (TCDW =148K) for SmNiC2 is gradually suppressed, while the ferromagnetic...
Year 2015
-
A large family of filled skutterudites stabilized by electron count
PublicationThe Zintl concept is important in solid-state chemistry to explain how some compounds that combine electropositive and main group elements can be stable at formulas that at their simplest level do not make any sense. The electronegative elements in such compounds form a polyatomic electron-accepting molecule inside the solid, a ‘polyanion’, that fills its available energy states with electrons from the electropositive elements...
-
Absence of superconductivity in fluorine-doped neptunium pnictide NpFeAsO
PublicationX-ray diffraction, specific heat, magnetic susceptibility and inelastic x-ray scattering measurements on the transurarium oxypnictides NpFeAsO and NpFeAsO0.85F0.15 are presented. No superconductivity down to 2 K was observed upon fluorine doping, contrary to the structurally analogous rare-earth pnictides. No modification of the phonon density of states was observed upon doping with fluorine. We discuss our results in light of...
-
Endohedral gallide cluster superconductors and superconductivity in ReGa5
PublicationWe present transition metal-embedded (T@Gan) endohedral Ga clusters as a favorable structural motif for superconductivity and develop empirical, molecule-based, electron counting rules that govern the hierarchical architectures that the clusters assume in binary phases. Among the binary T@Gan endohedral cluster systems, Mo8Ga41, Mo6Ga31, Rh2Ga9, and Ir2 Ga9 are all previously known superconductors. The well-known exotic superconductor...
-
Ferro- and antiferro-magnetism in (Np, Pu)BC
PublicationTwo new transuranium metal boron carbides, NpBC and PuBC, have been synthesized. Rietveld refinements of powder XRD patterns of {Np,Pu} BC confirmed in both cases isotypism with the structure type of UBC. Temperature dependent magnetic susceptibility data reveal antiferromagnetic ordering for PuBC below T-N = 44 K, whereas ferromagnetic ordering was found for NpBC below T-C = 61 K. Heat capacity measurements prove the bulk character...
-
KTaO3-based nanocomposites for air treatment
PublicationA series of single semiconductors and their nanocomposites combination (such as KTaO3 + CdSe + SrTiO3; KTaO3 + CdS +WO3; KTaO3 + CdS + MoS2) were prepared using hydrothermal route. Photocatalytic activity of as-prepared nanocomposites was estimated by photocatalytic degradation of toluene in the gas phase using light-emitting diodes (LEDs, 375 nm) in four subsequent cycles. The nanocomposites were characterized by scanning electron...
-
Microstructure and electrical properties of manganese borosilicate glasses
PublicationThe structure, optical and electrical properties of manganese borosilicate glasses of the composition xMnO–(80 − x)SiO 2 –20B 2 O 3 (x = 40, 50, and 60 mol%) were investigated. The dependence of the glass structure on its composition was discussed and related to electrical properties. A separation of two amorphous phases was observed. It was suggested that one phase is MnO-rich and the other is SiO 2 -rich. It was found that...
-
Perovskite-type KTaO3–reduced graphene oxide hybrid with improved visible light photocatalytic activity
PublicationNovel rGO–KTaO3 composites with various graphene content were successfully synthesized using a facile solvothermal method which allowed both the reduction of graphene oxide and loading of KTaO3 nanocubes on the graphene sheets. The as-prepared photocatalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), Fourier...
-
Pressure effects on the superconductivity of the HfPd2Al Heusler compound: Experimental and theoretical study
PublicationPolycrystalline HfPd2Al has been synthesized using the arc-melting method and studied under ambient-pressure conditions by x-ray diffraction from room temperature up to 450 °C. High-pressure x-ray diffraction up to 23 GPa was also performed using Diacell-type membrane diamond anvil cells. The estimated linear thermal expansion coefficient was found to be α=1.40(3)×10−5K−1, and the bulk modulus derived from the fit to the third-order...
-
Superconductivity in the niobium-rich compound Nb5Se4
PublicationThe niobium rich selenide compound Nb5Se4 was synthesized at ambient pressure by high-temperature solid–state reaction in a sealed Ta tube. Resistivity and heat capacity measurements reveal that this compound is superconducting, with a Tc = 1.85K. The electronic contribution to the specific heat γ and the Debye temperature are found to be 18.1 mJmol−1K−2 and 298 K respectively. The calculated electron-phonon coupling constant λep...
-
Unusual behaviour of (Np,Pu)B2C
PublicationTwo transuranium metal boron carbides, NpB2C and PuB2C have been synthesized by argon arc melting. The crystal structures of the {Np,Pu}B2C compounds were determined from single-crystal X-ray data to be isotypic with the ThB2C-type (space group R3m, a = 0.6532(2) nm; c = 1.0769(3) nm for NpB2C and a = 0.6509(2) nm; c = 1.0818(3) nm for PuB2C; Z = 9). Physical properties have been derived from polycrystalline bulk material in the...
Year 2014
-
237Np Mössbauer effect study on NpFeAsO
PublicationWe report 237Np Mössbauer measurements on NpFeAsO. The Np atoms were found to occupy only one crystallographic site. The value of the isomer shift (δ ∼ 9.1 mm s−1 versus NpAl2) indicates a 5f4 electronic configuration (Np3+ ions). The magnetic ordering of the Np sublattice below 60 K is established and the saturated ordered magnetic moment is determined to be 1.73μB at 3.6 K. The unique set of hyperfine parameters exclude a modulated...
-
Crystal structure and electronic structure of CePt2In7
PublicationWe report a corrected crystal structure for the CePt2In7 superconductor, refined from single crystal x-ray diffraction data. The corrected crystal structure shows a different Pt–In stacking along the c-direction in this layered material than was previously reported. In addition, all of the atomic sites are fully occupied with no evidence of atom site mixing, resolving a discrepancy between the observed high resistivity ratio of...
-
Evidence for SrHo2O4 and SrDy2O4 as model J1- J2 zigzag chain materials
PublicationNeutron diffraction and inelastic spectroscopy is used to characterize the magnetic Hamiltonian of SrHo2O4 and SrDy2O4. Through a detailed computation of the crystal-field levels we find site-dependent anisotropic single-ion magnetism in both materials, and diffraction measurements show the presence of strong one-dimensional spin correlations.Our measurements indicate that competing interactions of the zigzag chain, combinedwith...
-
KTaO3-based nanocomposites for air treatment
PublicationThe advantage is that photocatalytic methods allow removing VOCs, NOx, SO2, deodorants, and microorganisms at the same system. The new third generation of photoactive materials activated by low powered and low cost irradiation sources (such as LEDs or black fluorescent UV lamps) can be used as photocatalysts in air purification systems. A series of single semiconductors and their nanocomposites combination were prepared using hydrothermal...
-
Noncentrosymmetric superconductor with a bulk three-dimensional Dirac cone gapped by strong spin-orbit coupling
PublicationThe layered, noncentrosymmetric heavy element PbTaSe2 is found to be superconducting. We report its electronic properties accompanied by electronic-structure calculations. Specific heat, electrical resistivity, and magnetic-susceptibility measurements indicate that PbTaSe2 is a moderately coupled, type-IIBCSsuperconductor (Tc = 3.72 K, Ginzburg–Landau parameter κ = 17) with an electron-phonon coupling constant of λep = 0.74. Electronic-structure...
-
Superconducting properties and electronic structure of NaBi
PublicationResistivity, dc magnetization, and heat capacity measurements are reported for superconducting NaBi. Tc, the electronic contribution to the specific heat γ, the ΔCp/γTc ratio, and the Debye temperature are found to be 2.15 K, 3.4 mJ mol−1 K−2, 0.78, and 140 K respectively. The calculated electron–phonon coupling constant (λep = 0.62) implies that NaBi is a moderately coupled superconductor. The upper critical field and coherence...
-
Surface properties and photocatalytic activity of KTaO3, CdS, MoS2 semiconductors and their binary and ternary semiconductor composites
PublicationSingle semiconductors such as KTaO3, CdS MoS2 or their precursor solutions were combined to form novel binary and ternary semiconductor nanocomposites by the calcination or by the hydro/solvothermal mixed solutions methods, respectively. The aim of this work was to study the influence of preparation method as well as type and amount of the composite components on the surface properties and photocatalytic activity of the new semiconducting...
-
Surface Properties and Photocatalytic Activity of KTaO3, CdS, MoS2 Semiconductors and Their Binary and Ternary Semiconductor Composites
Publication -
Synthesis, single crystal growth and properties of Sr 5 Pb 3 ZnO 12
Publication -
Synthesis, single crystal growth and properties of Sr5Pb3ZnO12
PublicationAbstract The novel Sr5Pb3ZnO12 oxide was synthesized by the solid-state reaction method. The crystal structure was studied by means of the powder x-ray diffraction Rietveld method and was found to be similar to 3 other previously known Sr5Pb3MO12 compounds (M = Co, Ni, Cu). Crystals of several hundred microns in size of the new phase were grown in molten sodium chloride and imaged using confocal optical and scanning electron microscopy....
Year 2013
-
Magnetic properties of ferromagnetic Pu2Pt3Si5
PublicationThe structural, magnetic, and thermodynamic properties of a new plutonium based compound, Pu2Pt3Si5, are reported. Single crystals produced by a Sn-flux technique have been analyzed showing a ferromagnetic behavior at 58 K. Pu2Pt3Si5 crystallizes in the U2Co3Si5-type orthorhombic Iabm structure (s.g. 72) with atomic parameters a = 9.9226(2) Å, b = 11.4436(2) Å and c = 6.0148(1) Å. The effective (leff 0.74 lB/Pu) and saturated (rsat...
-
Measuring radioactive powder samples on the high-resolution powder diffraction beamline at the European Synchrotron Radiation Facility
Publication -
Measuring radioactive powder samples on the highresolution powder diffraction beamline at the European Synchrotron Radiation Facility
PublicationThis laboratory note describes a new sample preparation technique to enable high-resolution powder diffraction experiments at the European Synchrotron Radiation Facility on radioactive samples. The sample preparation involves setting the active material in resin and several layers of encapsulation suitable for measurement at the beamline. This has allowed low-temperature measurements on very small quantities of samples, providing...
-
Pressure-induced phase transitions in LnTe (Ln=La, Gd, Ho, Yb) and AmTe
PublicationThe structural behaviour under compression of different lanthanide (La, Gd, Ho, Yb) and actinide (Am) monochalcogenides is studied by means of in situ high-pressure x-ray diffraction. All the investigated compounds crystallize at ambient conditions within a cubic (B1) NaCl-type structure but show different behaviours at high pressures. LaTe and AmTe undergo B1 to B2 (CsCl-type structure) phase transitions, starting at 9 GPa and...
-
Structure and paramagnetism in weakly correlated Y8Co5
PublicationWe report the basic physical properties of monoclinic Y8Co5 determined by means of magnetic susceptibility, electrical resistivity, and specific heat measurements. The crystal structure of Y8Co5 is monoclinic (P21/c) with lattice parameters a = 7.0582(6) Å, b = 7.2894(6) Å, c = 24.2234(19) Å, and β = 102.112(6)° as refined by using synchrotron powder x-ray diffraction data. The compound shows temperature independent paramagnetism...
-
Superconductivity in the Cu(Ir1-xPtx)2Se4 spinel
PublicationWe report the observation of superconductivity in the CuIr2Se4 spinel induced by partial substitution of Pt for Ir. The optimal doping level for superconductivity in Cu(Ir1-xPtx )2Se4 is x = 0.2, where Tc is 1.76 K. A superconducting Tc vs composition dome is established between the metallic, normal conductor CuIr2Se4 and semiconducting CuIrPtSe4. Electronic structure calculations show that the optimal Tc occurs near the electron count...
-
Superconductivity in the Cu(Ir1−xPtx)2Se4spinel
Publication
Year 2012
-
Bulk properties and electronic structure of PuFeAsO
Publication -
Bulk properties and electronic structure of PuFeAsO
PublicationW pracy zamieszczone wyniki badań krystalograficznych, pomiarów ciepła właściwego i podatności magnetycznej na nowym związku PuFeAsO. PuFeAsO jest antyferromagnetykiem z T_N = 50 K.
-
Localized anharmonic rattling of Al atoms in VAl10.1
Publication -
Negative thermal expansion and antiferromagnetism in the actinide oxypnictide NpFeAsO
Publication -
Negative thermal expansion and antiferromagnetism in the actinide oxypnictide NpFeAsO
PublicationPrzeprowadzona został udana synteza NpFeAsO, związku będącego analogiem do LaFeAsO. Stwierdzono występowanie antyferromagnetycznego uporządkowania z T_N = 57 K. Poniżej T_N zauważono tzw. ujemną rozszerzalność termiczną. Przeprowadzono badania dyfrakcyjne przy użyciu promieniowania synchrotronowego (ESRF - Grenoble) a także neutronów (ILL - Grenoble).
-
Relation between Structure and Magnetic Properties of Microstructured PrAlO3
PublicationPrzedstawiono porównanie właściwości magnetycznych perowskitowego związku PrAlO3 i mikrostrukturalne wersji w formie eutektycznej PrAlO3 - PrAl11O18.
-
Superconductivity in the Einstein solid V Al10.1
Publication -
Superconductivity in the Einstein solid VAl10.1
PublicationWykonano pomiary podatności magnetycznej, oporu elektrycznego i ciepła właściwego dla VAl10.1. VAl10.1 jest nadprzewodnikiem II-go rodzaju z temperaturą krytyczną T_c = 1.53 K i górnym polem krytycznym 800 Oe.
-
Superconductivity in the Heusler family of intermetallics
Publication -
Superconductivity in the Heusler family of intermetallics
PublicationPrzeprowadzono badania szeregu związków nadprzewodzących z klasy związków Heuslera, w szczególności rodziny (Sc, Y, Lu)Pd2Sn i APd2M (A= Hf, Zr, i M = In, Al). Zwrócono uwagę na istotny wpływ sprzężenia elektron - fonon na obserwowane nadprzewodnictwo.
-
The comparison of SrTi0.98Nb0.02O3-δ-CeO2 and SrTi0.98Nb0.02O3-δ-YSZ composites for use in SOFC anodes
PublicationWytworzono i przebadano właściwości strukturalne i elektryczne kompozytów SrTi0.98Nb0.02O3-δ-CeO2 i SrTi0.98Nb0.02O3-δ-YSZ. Przeprowadzono testy materiałów zastosowanych jako anody w tlenkowych ogniwach paliwowych.
-
The comparison of SrTi0.98Nb0.02O3–δ-CeO2 and SrTi0.98Nb0.02O3–δ-YSZ composites for use in SOFC anodes
PublicationComposites of Nb-doped strontium titanate mixed with yttria-stabilized zirconia or cerium oxide in 50:50, 70:30 and 85:15 weight ratios were evaluated as possible anode/electrolyte interface materials for solid oxide fuel cells in terms of chemical compatibility, electrical conductivity and mechanical properties. It has been shown that composite samples prepared by typical powder-mixing methods remain single-phase up to 1400°C....
Year 2011
-
Crystal fields, disorder, and antiferromagnetic short-range order in Yb0.24Sn0.76Ru
Publication -
Crystal growth of CsCl-type Yb0.24Sn0.76Ru
Publication -
Crystal growth of CsCl-type Yb0.24Sn0.76Ru
PublicationWzrost kryształów o stechiometrii Yb0.24Sn0.76Ru został przeprowadzony metodą topnikową. Kryształy poddano badaniom dyfrakcyjnym a także mikroskopii elektornowej. Yb0.24Sn0.76Ru krystalizuje w sześciennej strukturze typu chlorku cezu (CsCl).
-
Crystal structure and physical properties of NpRh,Sn, a new Np-based ternary compound
Publication -
Retraction: Superconductivity in the Rh-based Heusler familyMRh2Sn[Phys. Rev. B82, 134520 (2010)]
Publication
Year 2010
-
Crystal structure and physical properties of NpRh2Sn, a new Np-based ternary compound
PublicationPoprzez syntezę w piecu łukowym został otrzymany nowy związek o stechiometrii NpRh2Sn. NpRh2Sn krystalizuje w strukturze ortorombowej i wykazuje przejście PM-AFM w temperaturze Neela T_N = 34K.
-
Influence of magnetic field on electronic conduction of (Bi,Pb)–Sr–Ca–Cu–O granular superconductors
Publication -
Magnetic Field Influence on the Superconducting Transition in Granular (BiPb)-Sr-Ca-Cu-O Superconductors
Publication -
Muon spin rotation/relaxation measurements of the noncentrosymmetric superconductorMg10Ir19B16
Publication -
Superconductivity in the Rh-based Heusler familyMRh2Sn
Publication
Year 2009
-
Ab initio Structure Determination of Mg10Ir19B16
Publication -
Ab initio Structure Determination of Mg10Ir19B16
PublicationOkreślono strukturę krystalograficzną nowego, nie-centrosymetrycznego nadprzewodzącego związku chemicznego, mg10ir19b16. Została zastosowana cała gama technik eksperymentalnych: dyfrakcja elektronowa, proszkowa dyfrakcja promieniowania rentgenowskiego, mikroskopia elektronowa wysokiej rozdzielczości, itd. Określenie struktury krystalograficznej było skrajnie trudne ponieważ jest to nowy, nieznany dotąd typ struktury krystalicznej,...
-
Cluster-glass behavior of a highly oxygen deficient perovskite, BaBi0.28Co0.72O2.2
PublicationZostała przeprowadzona synteza zwiąku typu perowskitowego BaBi0.28Co0.72O2.2. Stuktura krystalograficzna została określona poprzez dyfrakcję neutronową i promieniowania rentgenowskiego. Pomiary podatności magnetycznej AC i DC wskazują na zachowanie typu szkła klastrowego, które wynika z oddziaływań klastrów ferromagnetycznych.
-
First-order magnetic transition in single-crystalline CaFe2As2 detected by 75As nuclear magnetic resonance
PublicationPrzedstawione są wyniki badań jądrowego rezonansu magnetycznego na 75As dla kryształów CaFe2As2. Wyniki wskazują, że strukturalne i magnetyczne przejścia w CaFe2As2 są silnie skorelowane i są pierwszego rodzaju.
-
First-order magnetic transition in single-crystallineCaFe2As2detected byA75snuclear magnetic resonance
Publication -
Hybridization-driven gap in U3Bi4Ni3: A 209Bi NMR/NQR study
PublicationZostały przeprowadzone badania jądrowego rezonansu magnetycznego (na jądrach 209Bi) na kryształach U3Bi4Ni3. U3Ni4Bi3 jest tzw. izolatorem typu Kondo.
-
Hybridization-driven gap inU3Bi4Ni3: AB209iNMR/NQR study
Publication -
Insulator to correlated metal transition in V1−xMoxO2
PublicationDyskutowane jest przejście typu izolatro - metal w domieszkowanym atomami Molibdenu związku V1-xMoxO2. Prezentowany jest diagram fazowy.
-
Insulator to correlated metal transition inV1−xMoxO2
Publication -
Magnetic properties of the garnet and glass forms of Mn3Al2Si3O12
PublicationPrezentujemy wyniki pomiarow podatności magnetycznej i ciepła właściwego dla Mn3Al2Si3O12 w formie krystalicznej i amorficznej. W ten sposób przeprowadzamy porównania stopnia magnetycznej frustracji dla obu form tego samego związku chemicznego.
-
Magnetic properties of the garnet and glass forms ofMn3Al2Si3O12
Publication -
Ni2X2 (X = pnictide, chalcogenide, or B) based superconductors
PublicationPublikacja jest przeglądem właściwości nadprzewodników na bazie niklu, które zawierają płaszczyzny Ni2X2 (X=As, P, Bi, Si, Ge, B).
-
Ni2X2 (X=pnictide, chalcogenide, or B) based superconductors
Publication -
Stoichiometry, spin fluctuations, and superconductivity in LaNiPO
Publication -
Stoichiometry, spin fluctuations, and superconductivity in LaNiPO
PublicationZostała przeprowadzone synteza trzech próbek LaNiOP o różnych, nominalnie, składach. Najważniejszym wnioskiem pracy jest odkrycie, że nadprzewodnictw w LaNiPO jest niszczone już przez deficyt ok. 5% lantanu.
-
Superconductivity at 2.2 K in the layered oxypnictide La3Ni4P4O2
PublicationW pracy przedstawiamy odkrycie nowego, warstwowego, związku nadprzewodzącego La3Ni4P4O2.
-
Superconductivity at 2.2 K in the layered oxypnictideLa3Ni4P4O2
Publication
Year 2008
-
Crystal structure and physical properties of Mg6Cu16Si7-type M6Ni16Si7, for M=Mg, Sc, Ti, Nb, and Ta
Publication -
Crystal structure and physical properties of Mg6Cu16Si7-typeM6Ni16Si7, for M = Mg, Sc, Ti, Nb, and Ta
PublicationW pracy dyskutowana jest synteza i struktura krystalograficzna, określona poprzez proszkową dyfrakcję rentgenowską, dla pięciu związków M6Ni16Si7, gdzie M = Mg, Sc, Ti, Nb, and Ta. Wszystkie te związki krystalizują w strukturze typu Mg6Cu16Si7.
-
Magnetism and structure of Li_xCoO2 and comparison to Na_xCoO2
PublicationW pracy dyskutowane są właściwości magnetyczne i strukturalne Li_xCoO2 dla 0.5< x< 1.0. Jon Co +4 znajduje się w stanie wysokospinowym w Li_xCoO2 dla zawartości litu od 0.94 do 1.00 i w stanie niskospinowym dla x od 0.50 do 0.78.
-
Magnetism and structure ofLixCoO2and comparison toNaxCoO2
Publication -
Microscopic 75^As NMR study of the effect of impurities on the first-order spin-density-wave transition in BaFe2As2
PublicationOpisane są wyniki badań NMR na 75^As w monokryształach i próbkach polikrystalicznych BaFe2As2. Zanieczyszczenia cyną wpływają na niskoenergetyczne fluktuacje spinowe i obniżają temperaturę krytyczną ze 138K do 85K.
-
MicroscopicA75sNMR study of the effect of impurities on the first-order spin-density-wave transition inBaFe2As2
Publication -
Physical properties of the uranium ternary compounds U3Bi4M3 (M=Ni,Rh)
PublicationW pracy dyskutowany jest wzrost kryształów i właściwości fizyczne dwóch, nowych, izostrukturalnych związków U3Bi4Ni3 i U3Bi4Rh3. Pierwszy z nich jest nie-metalem, w drugim obserwowany jest tzw. ferromagnetyczny kwantowy punkt krytyczny.
-
Physical properties of the uranium ternary compoundsU3Bi4M3(M=Ni,Rh)
Publication -
Pressure-induced superconductivity in CaFe2As2
PublicationNowo odkryty związek CaFe2As2 pod wpływem zewnętrznego ciśnienia 0.69 GPa przechodzi w stan nadprzewodnictwa z temperaturą krytyczną powyżej 10K.
-
Successive orbital ordering transitions in NaVO2
PublicationPomiary właściwości fizycznych NaVO2, który charakteryzuje się trójkątną siecią krystalograficzną, pokazują dwa przejścia typu orbitalnego. W temperaturze 98 K w systemie wystepuje przejście drugiego rodzaju. Natomiast poniżej 93 K obserwowane jest przejście pierwszego rodzaju.
-
Successive Orbital Ordering Transitions inNaVO2
Publication