Impacts of nanostructuring and magnetic ordering of Nd3+ on the magnetic and magnetocaloric response in NdMnO3

作者：Chandra Sayan; Biswas Anis; Phan Manh Huong; Srikanth Hariharan^*

来源：Journal of Magnetism and Magnetic Materials, 2015, 384: 138-143.

DOI：10.1016/j.jmmm.2015.02.032

• Complex oxides
• Magnetism
• Magnetocaloric effect

Magnetocaloric properties of NdMnO3 were investigated in its bulk polycrystalline and nanocrystalline forms. The nanocrystalline sample (average particle size similar to 40 nm) exhibits a maximum in the temperature dependence of magnetic entropy change [-Delta S-M(T)] at similar to 70 K due to the paramagnetic to ferromagnetic transition, which is absent in case of its bulk counterpart. The absence of peak in -Delta S-M(T) in the bulk sample is attributed to the co-existence of antiferromagnetic and ferromagnetic phases. A canted magnetic state (CMS) is stabilized at low temperature for both the samples due to the ordering of Nd3+ giving rise to a peak in -Delta S-M(T) at similar to 15 K. Interestingly -Delta S-M(T) for these two samples show a universal behavior near their transitions at low temperature although their temperature dependence of magnetization is markedly different around those transitions. A detailed analysis of magnetocaloric data conclusively establishes the existence of a canted magnetic state, which is not obvious from magnetometry, demonstrating the usefulness of this method for probing phase coexistence and multiple magnetic states in complex oxide systems.

• 出版日期2015-6-15