Ferromagnetic feature from Mn near room temperature in the fine particles of GdMn2Ge2 and TbMn2Ge2
Tata Institute of Fundamental Research - Homi Bhabha Road, Colaba, Mumbai-400005, India
Corresponding author: email@example.com
Accepted: 1 April 2010
The magnetization behaviors of GdMn2Ge2 and TbMn2Ge2 in the bulk and in the fine particles (<1 μm) obtained by high-energy ball-milling are compared. Pronounced modifications in the spontaneous, remanent and high-field magnetization in the fine-particle form, attributable to Mn, are observed. The results indicate that the antiferromagnetism of Mn sublattice known for the bulk form in the range ~ 100–300 K gets weakened in favor of ferromagnetism in the fine particles. On the basis of this observation, we infer that there are other factors like size (and possibly defects) also play a role to decide the exact nature of magnetic ordering of Mn in this ternary family of materials, in contrast to the traditionally held view that the basal plane Mn-Mn distance is the crucial controlling parameter.
PACS: 75.50.Tt – Fine-particle systems; nanocrystalline materials / 75.30.Kz – Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.) / 75.50.Ee – Antiferromagnetics
© EPLA, 2010