The system HoAl3(BO3)4 has recently been found to exhibit a large magnetoelectric effect. To understand the mechanism, macroscopic and atomic level properties of HoAl3(BO3)4 were explored by temperature and magnetic field dependent heat capacity measurements, pressure and temperature dependent x-ray diffraction measurements, as well as temperature and magnetic field dependent x-ray absorption fine structure measurements. The experimental work was complemented by density functional theory calculations. An anomalous change in the structure is found in the temperature range where large magnetoelectric effects occur. No significant structural change or distortion of the HoO6 polyhedra is seen to occur with magnetic field. However, the magnetic field dependent structural measurements reveal enhanced correlation between neighboring HoO6 polyhedra. This observed response is seen to saturate near 3 T. A qualitative atomic level description of the mechanism behind the large electric polarization induced by magnetic fields in the general class of RAl3(BO3)4 systems (R= rare earth) is developed.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Sep 23 2015|
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics