The concept of high-entropy oxides has triggered extensive research of this novel class of materials because their numerous functional properties are usually not mere linear combinations of those of the components. Here, we introduce the new series of compositionally complex honeycomb-layered magnets NaLiTSbO (T = CuNiCo). An unusual feature of the system is its nonmonotonous dependences of the monoclinic lattice parameters and β on .
View Article and Find Full Text PDFThe non-stoichiometric system LiNiSbO is a Li-deficient derivative of the zigzag honeycomb antiferromagnet LiNiSbO. Structural and magnetic properties of LiNiSbO were studied by means of X-ray diffraction, magnetic susceptibility, specific heat, and nuclear magnetic resonance measurements. Powder X-ray diffraction data shows the formation of a new phase, which is Sb-enriched and Li-deficient with respect to the structurally honeycomb-ordered LiNiSbO.
View Article and Find Full Text PDFElectrochemical characterization of the novel sodium iron titanate NaFeTiO was performed upon cycling in the Li-ion half-cell. The material exhibited stable cycling in the voltage range 2-4.5 V, and the number of alkali ions extracted per formula unit was approximately half of the Na stoichiometry value.
View Article and Find Full Text PDFWe report the first four magnetic representatives of the trigonal layered AM(4+)TeO (here, M = Mn) family. NaMnTeO was synthesized from NaMnO, NaNO, and TeO at 650-720 °C, but analogues for which A = Li and K could not be obtained by direct synthesis. However, those for which A = Li, Ag, and Tl (but not K) were prepared by exchange reactions between NaMnTeO and the corresponding molten nitrates.
View Article and Find Full Text PDFFour new manganese germanates and silicates, AMnGeO (A = Li, Na) and AMnSiO (A = Na, Ag), were prepared, and their crystal structures were determined using the X-ray Rietveld method. All of them contain all components in tetrahedral coordination. LiMnGeO is orthorhombic (Pmn2) layered, isostructural with LiCdGeO, and the three other compounds are monoclinic (Pn) cristobalite-related frameworks.
View Article and Find Full Text PDFA new layered trigonal (P3̅1m) form of MnSb2O6, isostructural with MSb2O6 (M = Cd, Ca, Sr, Pb, and Ba) and MAs2O6 (M = Mn, Co, Ni, and Pd), was prepared by ion-exchange reaction between ilmenite-type NaSbO3 and MnSO4-KCl-KBr melt at 470 °C. It is characterized by Rietveld analysis of the X-ray diffraction pattern, electron microprobe analysis, magnetic susceptibility, specific heat, and ESR measurements as well as by density functional theory calculations. MnSb2O6 is very similar to MnAs2O6 in the temperature dependence of their magnetic susceptibility and spin exchange interactions.
View Article and Find Full Text PDF