標題: | Strain-induced effects on antiferromagnetic ordering and magnetocapacitance in orthorhombic HoMnO3 thin films |
作者: | Lin, T. H. Shih, H. C. Hsieh, C. C. Luo, C. W. Lin, J-Y Her, J. L. Yang, H. D. Hsu, C-H Wu, K. H. Uen, T. M. Juang, J. Y. 電子物理學系 物理研究所 Department of Electrophysics Institute of Physics |
公開日期: | 14-一月-2009 |
摘要: | We investigated the magnetic and ferroelectric properties of c-axis oriented orthorhombic phase HoMnO3 (o-HMO in Pbnm symmetry setting) thin films grown on Nb-doped SrTiO3(001) substrates. The o-HMO films exhibit an antiferromagnetic ordering near 42 K, irrespective of the orientation of the applied field. However, an additional magnetic ordering occurring around 35 K was observed when the field was applied along the c-axis of o-HMO, which was absent when the field was applied in the ab-plane. The magnetocapacitance measured along the c-axis showed that although there is evidence of dielectric constant enhancement when the temperature is below 35 K the expected abrupt change in dielectric constant appears at a much lower temperature and reaches maximum around 13.5 K, indicating that the low-temperature c-axis polarization might be related to the ordering of the Ho3+ moment. The lattice constant analyses using x-ray diffraction and the observation of a slight magnetization hysteresis suggest that the weak second magnetic transition along the c- axis at 35 K might be more relevant to the strain-induced effect on antiferromagnetism. |
URI: | http://dx.doi.org/10.1088/0953-8984/21/2/026013 http://hdl.handle.net/11536/149634 |
ISSN: | 0953-8984 |
DOI: | 10.1088/0953-8984/21/2/026013 |
期刊: | JOURNAL OF PHYSICS-CONDENSED MATTER |
Volume: | 21 |
顯示於類別: | 期刊論文 |