Neutron polarization analysis on the multiferroic TbMn2O5

Polycrystalline TbMn2O5 was prepared by the standard solid-state reaction method and characterized by powder X-ray diffraction and magnetization to assure it is of single phase. Heat capacity measurements on the compound reveal an antiferromagnetic phase transition at similar to 45 K. A broad peak below similar to 6 K in the heat capacity measurements corresponds to the crossover transition of Tb3+ ordering. To confirm these magnetic orderings, neutron powder diffractions on TbMn2O5 with XYZ neutron polarization analysis were performed at the diffuse neutron scattering (DNS) spectrometer, FRJ-II, by using neutron wavelength of 4.8 angstrom in the temperature range of 1.8-250 K. Magnetic scattering was separated from nuclear coherent and spin incoherent scattering contributions. Long-range ordered magnetic peaks were observed below similar to 39 K which is consistent with the heat capacity results. The drastic increasing intensities below similar to 6 K indicate the ferromagnetic transition in Tb3+ orderings. (C) 2009 Elsevier B.V. All rights reserved.