Spin-phonon coupling in PrMn₂O₅ nanorods
Ting-Wei Hsu1*, Chung-Cheun Yang1, Huo-Yen Chen1, Hsi-Sheng Hsia1, Kuen-Song Lin1
1Department of Physics, Chung Yuan Christian University, 200, Chung Pei Rd., Chung Li 32023, Taiwan
2Department of Chem. Eng. and Mat. Sci., Yuan Ze University, Chung Li, Taiwan
* presenting author:許庭瑋, email:myshine852@gmail.com
PrMn2O5 nanorods with five axial () × radial lengths of 63 nm×25 nm, 150 nm×25 nm, 152 nm×29 nm, 259 nm×86 nm, and 262 nm×87 nm were fabricated by the hydrothermal method. Experiments on magnetic susceptibility demonstrate ICAFM (TN) and ICAFM-to-CAFM (TN’) ordering at 43 K and 20 K, respectively, in the samples with  259 nm. At = 262 nm, both TN and TN’ are shifted to higher temperatures and the samples exhibit magnetic correlation from 150 K. Experimentally obtained M-H curves demonstrate that only the sample with = 262 nm exhibits a hysteresis loop. Raman spectra obtained at various temperatures reveal that in only the sample with = 262 nm does the Ag + B1g mode exhibit a large Raman shift until the sample is cooled to 150 K. The distinctiveness of the = 262 nm sample arises from annealing. This treatment reduces the barrier to magnetic ordering that is caused by defects and promotes spin-phonon coupling at high temperatures.

Keywords: multiferroic, spin-phonon, size effect, nanorod, magnetic