Neutron diffraction study and magnetotransport properties of stoichiometric CaMoO{sub 3} perovskite prepared by a soft-chemistry route
- Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco, 28049 Madrid (Spain)
- Laboratory for Neutron Scattering, ETHZ and PSI, CH-5232 Villigen PSI (Switzerland)
Polycrystalline CaMoO{sub 3} perovskite has been prepared by soft-chemistry procedures, followed by controlled annealing under reducing conditions (H{sub 2}/N{sub 2} flow). The crystal structure, studied from neutron powder diffraction data, can be described in an orthorhombic unit cell, space group Pbnm (No. 62). The lattice parameters were a=5.4510(1) A, b=5.5821(1) A and c=7.7803(2) A. In the perovskite network the MoO{sub 6} octahedra are tilted by 13.5 deg. in order to optimize the Ca-O bond lengths; the tilting scheme corresponds to a GdFeO{sub 3}-like superstructure. The perovskite is fully oxygen stoichiometric, as demonstrated from the refinement of the oxygen occupancy factors. Resistivity and transport measurements indicated that CaMoO{sub 3} behaves as a metal; at low temperatures (5 K) a small positive magnetoresistance is observed, reaching a maximum value of 1.4% at 9 T. The magnetic susceptibility is predominantly Pauli paramagnetic-like, although a non-negligible temperature-dependent component due to isolated Mo{sup 4+} spins is patent at low temperatures. - Graphical abstract: CaMoO{sub 3} is an orthorhombic perovskite (Pbnm) where the MoO{sub 6} octahedra are tilted by 13.5 deg. (a). It is a Pauli paramagnet (b) and at low temperatures (5 K) presents a small positive magnetoresistance (c)
- OSTI ID:
- 20905293
- Journal Information:
- Journal of Solid State Chemistry, Vol. 179, Issue 6; Other Information: DOI: 10.1016/j.jssc.2006.02.022; PII: S0022-4596(06)00095-8; Copyright (c) 2006 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
Similar Records
A structural study of the perovskite series Na{sub 0.75}Ln{sub 0.25}Ti{sub 0.5}Nb{sub 0.5}O{sub 3}
On the red phosphor of nominal composition Gd{sub 0.77}Al{sub 1.23}O{sub x}:Eu{sub 0.06} (x{approx}3.1)