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arXiv · 2112.13080

Three-dimensional ferrimagnetic ground state of triangular-lattice system Ca3Co2O6

Santanu De·V. R. Reddy·A. Banerjee
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Abstract

High temperature one-dimensional (1D) ferromagnetic (FM) chains in Ca3Co2O6 spin system are subjected to a magnetic field and temperature induced first order phase transition (FOPT) to 3D ferrimagnetic (FIM) ground state with decrease in temperature (T). Weak-FM interaction of third nearest-neighbor(nn) interchain removes the frustration effect arising from antiferromagnetic (AFM) interactions of first-nn and second-nn interchains in the underlying triangular-lattice resulting a 3D FIM ordering of 1D FM chains at low T. However, hindered kinetics of FOPT partially masks this tranformation giving rise to coexistence of non-interacting 1D FM chains with 3D-FIM state at low-T. The existence of all these couplings is further confirmed here by random substitution of S = 5/2 magnetic-impurity into the spin chain of original system. It reveals weakening of FM interactions of both intrachain and third-nn surrounding chains respectively without significant modulation in the AFM coupling of first-nn and second-nn interchains. Thus, influence of AFM interactions is enhanced as compared to effective FM coupling with increase of S = 5/2 impurity content resulting instability of 3D long-range FIM state at low-T.

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Santanu De, V. R. Reddy, A. Banerjee. 2021-12-24. Three-dimensional ferrimagnetic ground state of triangular-lattice system Ca3Co2O6. https://doi.org/10.1016/j.jmmm.2025.173000

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