Synthesis and Properties of NdNiO(3) Prepared by Low Temperature Methods.

摘要

NdNiO3 has been prepared with a rhombohedral perovskite structure by low temperature methods, and its magnetic and electric properties have been studied between 4 K and 300 K. The temperature coefficient of the resistivity changes at 130 K from positive (i.e., metal-like) to negative (i.e., semiconductor-like), with some thermal hysteresis at this 'transition'. The magnetic susceptibility shows Curie-Weiss behavior, modified by the changing thermal occupation of the Nd+3 crystal field levels, over the whole temperature range. Differential thermal analysis and thermogravimetric analysis showed oxygen loss beginning at 900 C in an N2 atmosphere. Subsequent xray analysis at room temperature showed the presence of Nd2NiO4 and NiO. The electrical resistivity of sintered polycrystalline samples is somewhat above the expected minimum metallic conductivity, but the observation of a positive constant term in the susceptibility above 100K suggests metallic band behavior. Keywords: Oxide conductors; Structural phase transitions; Perovskites. (jes)