High-pressure preparation and characterization of (R,R')NiO3 (R,R'= rare earths) perovskites: effect of the variance of the R3+ ionic sizes

6th Meeting of the Spanish Neutron Scattering Association

Martínez-Lope, M.J.^1 ; Sánchez-Benítez, J.^2 ; Fernandez-Díaz, M.T.^3 ; Alonso, J.A.^1

Instituto de Ciencia de Materiales de Madrid (CSIC), Madrid

E-28049, Spain^1

Departamento de Química Física i, Fac. CC. Químicas, Universidad Complutense de Madrid, Madrid

E-28040, Spain^2

Institut Laue Langevin, BP 156X, Grenoble

F-38042, France^3

关键词: Charge disproportionation;    Coordination environment;    High-resolution neutron powder diffraction;    Insulating state;    Mixed rare earth;    Monoclinic distortion;    Structural feature;    Three-dimensional networks;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/549/1/012023/pdf
DOI  :  10.1088/1742-6596/549/1/012023

来源: IOP

【 摘 要 】

In this paper we describe some novel members of the RNiO3perovskites, containing Ni3+and presenting metal-insulator transitions coupled to a charge disproportionation effect. This phenomenon is observed in the insulating state as a subtle monoclinic distortion, due to the presence of two unequivalent Ni ions with different coordination environments, corresponding to expanded and contracted octahedra alternating in the three-dimensional network. Here we examine how the introduction of mixed rare-earth cations at the R sublattice affects the metal-insulator transition and the structural features, from high resolution neutron powder diffraction studies.