Metal–Insulator Transitions Induced by Doping in LaNiO3: LaNi0.95M0.05O3(M=Mo, W, Sb, Ti, Cu, Zn) Perovskites
✍ Scribed by I Álvarez; M.L Veiga; C Pico
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 305 KB
- Volume
- 136
- Category
- Article
- ISSN
- 0022-4596
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✦ Synopsis
Structural characterization and electronic properties of the LaNi 0.95 M 0.05 O (M ؍ Mo, W, Sb, Ti, Cu, Zn) perovskite-like system are reported. These compounds can be regarded as being derived from LaNiO by partial substitution of Ni> in this material by M 6؉ , M 5؉ , M 4؉ , or M 2؉ formal cations, with a partial reduction of Ni 3؉ to Ni 2؉ taking place. X-ray powder diffraction data were analyzed by means of the Rietveld method and show that all the title materials present perovskite-type structure with a rhombohedral (S.G. R3 c) or orthorhombic (S.G. Pbnm) symmetry, depending on the nature of the M cation. In all cases, Ni and M cations are placed at random in octahedral B-sites of perovskite structure. Electrical resistivity measurements (four probe method) show metal-to-insulator (M-I) transitions for M ؍ Mo, W, Ti, Cu, Zn at temperatures of about 50 K and a semiconductor behavior for the Sb sample in the whole temperature range explored. Magnetic susceptibility measurements show the presence of weak ferromagnetic interactions for M ؍ Sb and Pauli paramagnetism for the remaining compounds.