Crystal field and magnetism of Pr${}^{3+}$ and Nd${}^{3+}$ ions in orthorhombic perovskites

Abstract

Fifteen parameters characterizing the crystal field of rare-earth ions in the RMO${}_3$ perovskites (R = Pr, Nd, M = Ga, Co) are calculated by expanding the local Hamiltonian expressed in the basis of Wannier functions into a series of spherical tensor operators. The method contains a single adjustable parameter that characterizes the hybridization of R($4f$) states with the states of oxygen ligands. Subsequently the energy levels and magnetic moments of trivalent R ion are determined by diagonalization of an effective Hamiltonian which, besides the crystal field, contains the $4f$ electron-electron repulsion, spin-orbit coupling and interaction with magnetic field. In the Ga compounds the energy levels of the ground multiplet agree within few meV with those determined experimentally by other authors. For all four compounds in question the temperature dependence of magnetic susceptibility is measured on polycrystalline samples and compared with the results of calculation. For NdGaO${}_3$ theory is also compared with the magnetic measurements on a single crystal presented by Luis {\it et al.} Phys. Rev. B {\bf 58}, 798 (1998). A good agreement between the experiment and theory is found.

References in corpus (3)

• Spin state transition and covalent bonding in LaCoO3
• Crystal field with Wannier functions: Application to rare-earth aluminates
• The ground state properties of the mixed-valence cobaltites Nd${}_{0.7}$Sr${}_{0.3}$CoO${}_3$, Nd${}_{0.7}$Ca${}_{0.3}$CoO${}_3$ and Pr${}_{0.7}$Ca${}_{0.3}$CoO${}_3$

Cited by in corpus (7)

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• On the possibility of excitonic magnetism in Ir double perovskites
• Magnetic properties of RCoO${}_3$ cobaltites (R = La, Pr, Nd, Sm, Eu). Effects of hydrostatic and chemical pressure
• The spin-state crossover and low-temperature magnetic state in yttrium doped Pr${}_{0.7}$Ca${}_{0.3}$CoO${}_3$
• Magnetic-field-induced spin crossover of Y-doped Pr${}_{0.7}$Ca${}_{0.3}$CoO${}_3$
• Spin Hall magnetoresistance in paramagnetic NdGaO3
• Crystal field calculations for transition metal ions by application of an opposing potential