Stabilization of A-site ordered perovskites and formation of spin-half antiferromagnetic lattice: CaCu$_3$Ti$_4$O$_{12}$ and CaCu$_3$Zr$_4$O$_{12}$

Jatin Kumar Bidika; Amit Chauhan; B. R. K. Nanda

doi:10.1103/PhysRevB.106.115152

paper

Stabilization of A-site ordered perovskites and formation of spin-half antiferromagnetic lattice: CaCu $_{3}$ Ti $_{4}$ O $_{12}$ and CaCu $_{3}$ Zr $_{4}$ O $_{12}$

arXiv:2208.10348 · doi:10.1103/PhysRevB.106.115152

Abstract

A-site ordered perovskites, CaCu $_{3}$ B $_{4}$ O $_{12}$ , which are derivatives of conventional ABO $_{3}$ perovskites, exhibit varying electronic and magnetic properties. With the objective of examining the role of Cu in this work, we have studied CaCu $_{3}$ Ti $_{4}$ O $_{12}$ and CaCu $_{3}$ Zr $_{4}$ O $_{12}$ and presented the cause of the crystallization of A-site ordered perovskite from conventional ABO $_{3}$ perovskite and the underlying mechanism leading to the stabilization of non-trivial and experimentally estabilished G-type antiferromagnetic (G-AFM) ordering in these systems. The first-principles electronic structure calculations supplemented with phonon studies show that the formation of A-site ordered perovskite is driven by Jahn-Teller distortion of the CuO $_{12}$ icosahedron. The crystal orbital Hamiltonian population analysis and magnetic exchange interactions estimated using spin dimer analysis infers that the nearest and next-nearest-neighbor interactions (J $_{1}$ and J $_{2}$ ) are direct and weakly ferromagnetic whereas the third-neighbor interaction (J $_{3}$ ) is unusually strong and antiferromagnetic driven by indirect superexchange mechanism. The structural geometry reveals that stabilization of G-AFM requires J $_{1}$ $<$ 2J $_{2}$ , J $_{1}$ $<$ 2J $_{3}$ . The experimental and theoretical values of Neel Temperature agrees well for $U$ $\approx$ 7 eV, highlighting the role of strong correlation. The magnetic ordering is found to be robust against pressure and strain.

Stabilization of A-site ordered perovskites and formation of spin-half antiferromagnetic lattice: CaCu3​Ti4​O12​ and CaCu3​Zr4​O12​

Abstract

References in corpus (11)

Stabilization of A-site ordered perovskites and formation of spin-half antiferromagnetic lattice: CaCu $_{3}$ Ti $_{4}$ O $_{12}$ and CaCu $_{3}$ Zr $_{4}$ O $_{12}$