Il Nuovo Cimento A

, Volume 63, Issue 1, pp 71–75 | Cite as

Superparamagnetic resonance in fine-grained antiferromagnetic oxides

  • K. G. Srivastava
  • R. Srivastava


The resonance line widths (ΔH) in the X-band for fine-grained Cr2O3 and α-Fe2O3, as obtained experimentally, are given. The half-power line widths ΔH are found to increase as temperature is lowered, and their variations with temperature above 2000K are explained by rotation of the net magnetic moment of the grain according to the thermal activation process. The magnetic potential barriers are calculated to be small, being of the order of 10−3 eV.


Line Width Anisotropy Field Exchange Narrowing Antiferromagnetic Resonance Thermal Activation Process 
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Si danno le ampiezze della linea di risonanza (ΔH) nella banda X per Cr2O3 e α-Fe2O3 a grana fine, ottenute sperimentalmente. Si trova che le ampiezze della linea ΔH di metà potenza crescono con l'abbassarsi della temperatura, e si spiegano le loro variazioni con temperature superiori a 200oK con la rotazione del momento magnetico netto dei grani secondo il processo di attivazione termica. Si calcola che le barriere di potenziale magnetico siano piccole, cioè dell'ordine di 10−3 eV.


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Copyright information

© Società Italiana di Fisica 1965

Authors and Affiliations

  • K. G. Srivastava
    • 1
  • R. Srivastava
    • 1
  1. 1.Physics DepartmentUniversity of AllahabadAllahabad

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