Size effect on magnetic properties of hexagonal HoMnO3 nanoparticles

作者：Han T C^*; Tsai M R; Wei C Y

来源：Journal of Applied Physics, 2011, 109(7): 07B517.

DOI：10.1063/1.3556945

We have synthesized a series of hexagonal HoMnO3 nanoparticles with different particle sizes (30 - 200 nm) by a modified Pechini method to study systematically the effect of particle size on their structural and magnetic properties. The magnetic characterization indicates that with increasing the particle size, the antiferromagnetic (AFM) transition temperature increases from 50 to 70 K. Further analysis suggests that the rising of AFM transition temperature with the increasing particle size should be from the structural origin, in which the strength of AFM interaction is dependent on the in-plane lattice parameters. Furthermore, with a decrease in particle size, the Mn-spin reorientation temperature (T-SR) is enhanced from 39 to 43 K. These results show an important coupling between the Mn3+ and Ho3+ ion spins as well as a T-SR that is driven by the cooperative MnO5 site rotation.

• 出版日期2011-4-1