TY - JOUR
T1 - Magnetoelectric effect in a spin-state transition system
AU - Naka, Makoto
AU - Mizoguchi, Eriko
AU - Nasu, Joji
AU - Ishihara, Sumio
N1 - Funding Information:
Acknowledgments We thank M. Azuma for his helpful discussions. This work was supported by MEXT KAKENHI Grant Nos. JP26287070, JP15H02100, JP16H00987, JP16K17747, and JP16K17731. Some of the numerical calculations were performed using the facilities of the Supercomputer Center at the Institute for Solid State Physics, University of Tokyo.
Publisher Copyright:
©2018 The Physical Society of Japan
PY - 2018
Y1 - 2018
N2 - Magnetic, dielectric, and magnetoelectric properties in a spin-state transition system are examined, motivated by the recent discovery of multiferroic behavior in a cobalt oxide. We construct an effective model Hamiltonian on the basis of the two-orbital Hubbard model, in which the spin-state degrees of freedom in magnetic ions couple with ferroelectric-type lattice distortions. A phase transition occurs from the high-temperature low-spin phase to the low-temperature high-spin ferroelectric phase with an accompanying increase in spin entropy. The calculated results are consistent with the experimental pressure-temperature phase diagram. We predict the magnetic-field induced electric polarization in the low-spin paraelectric phase near the ferroelectric phase boundary.
AB - Magnetic, dielectric, and magnetoelectric properties in a spin-state transition system are examined, motivated by the recent discovery of multiferroic behavior in a cobalt oxide. We construct an effective model Hamiltonian on the basis of the two-orbital Hubbard model, in which the spin-state degrees of freedom in magnetic ions couple with ferroelectric-type lattice distortions. A phase transition occurs from the high-temperature low-spin phase to the low-temperature high-spin ferroelectric phase with an accompanying increase in spin entropy. The calculated results are consistent with the experimental pressure-temperature phase diagram. We predict the magnetic-field induced electric polarization in the low-spin paraelectric phase near the ferroelectric phase boundary.
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U2 - 10.7566/JPSJ.87.063709
DO - 10.7566/JPSJ.87.063709
M3 - Article
AN - SCOPUS:85047940624
SN - 0031-9015
VL - 87
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
IS - 6
M1 - 063709
ER -