Néel temperature enhancement in nanostructured nickel zinc ferrite

• Published in: Applied physics letters Vol. 86; no. 19; pp. 192510 - 192510-3
• Main Authors: Ponpandian, N., Narayanasamy, A., Chinnasamy, C. N., Sivakumar, N., Greneche, J.-M., Chattopadhyay, K., Shinoda, K., Jeyadevan, B., Tohji, K.
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 09-05-2005
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/1.1925755

The Néel temperature of
Ni
0.5
Zn
0.5
Fe
2
O
4
spinel ferrite increases significantly from
538
K
in the bulk state to
592
K
when the grain size is reduced to
16
nm
by milling in a high-energy ball mill. This has been attributed to an increase in the AB superexchange interaction strength due to a possible enhancement in the magnetic ion concentration in the A-site on milling, as is evident from extended x-ray absorption fine structure and in-field Mössbauer measurements.