No abstract

Structure and magnetic properties of nickel oxide (NiO) nanopowders have been studied by X-ray/neutron diffraction, SQUID magnetometer, and micro-Raman spectroscopy. Our diffraction data indicate that at room temperature all NiO powders are antiferromagnetically ordered and have a rhombohedral (R-3m) phase. The SQUID magnetometry and Raman spectroscopy measurements support the presence of the antiferromagnetic ordering.

No abstract

No abstract

Crystal structure investigations, electrical resistivity, and magnetic measurements have been performed for polycrystalline samples of intercalated compounds Cr(x)TiTe(2) with a Cr concentration up to x = 0.65. According to the room-temperature x-ray diffraction study of Cr(x)TiTe(2), the initial hexagonal crystal structure transforms to a monoclinic one with increasing Cr content up to x≥0.5 due to the ordering of Cr ions. The intercalation results in the change of the resistivity behavior in Cr(x)TiTe(2) from metal-like at x = 0 to insulator-like above x = 0.33 and leads to ferromagnetic ordering of Cr magnetic moments at x≥0.5. For the compound Cr(0.25)TiTe(2), structural transformations and anomalous resistivity behavior are observed around 230 K, which cannot be explained only by the order-disorder transition within the subsystem of intercalated Cr ions. Structural changes within Te-Ti-Te sandwiches associated with charge density wave instability are suggested to be involved in this phase transition as well.

No abstract

No abstract

No abstract