Abstract
Recently discovered magnetoelectricity in the rare-earth aluminum borates RAl(BO) has attracted attention due to the large values of magnetoinduced electric polarization. We have observed for the first time the magnetoelectric polarization in TbAl(BO) exhibiting anomalous temperature dependence: an electric polarization induced by in-plane magnetic field ( axis) which is small at low temperatures (), remarkably increases by almost an order of magnitude at high temperatures (). The observed nonmonotonic temperature behavior of the field-induced polarization, including a change of sign at , is attributed to the competition of the ground and excited crystal-field states of Tb ions. Quantum theory analysis, involving the combination of analytical and numerical methods, has enabled us to quantitatively describe the observed magnetic and magnetoelectric properties of TbAl(BO).
- Received 13 September 2013
- Revised 3 January 2014
DOI:https://doi.org/10.1103/PhysRevB.89.014418
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