, Volume 2, Issue 4, pp 226–228 | Cite as

Crystal shape effect on nuclear orientation thermometry at ultra-low temperatures

  • T S Radhakrishnan
  • Girish Chandra
Instruments And Techniques


Absolute temperature measurement (T < 100 mK region) from anisotropy of gamma radiations emitted from oriented60Co nuclei in a single crystal of hcp cobalt is found to depend on the shape of the crystal. This dependence is attributed to some closure magnetic domains not oriented along thec-axis of the disc shaped crystal studied. A long rectangular strip of cobalt crystal is found to give correct angular distribution ofγ-radiations and, therefore, suitable for thermometry.


Ultra-low temperatures nuclear orientation thermometry closure domains 


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Copyright information

© the Indian Academy of Sciences 1974

Authors and Affiliations

  • T S Radhakrishnan
    • 1
  • Girish Chandra
    • 1
  1. 1.Tata Institute of Fundamental ResearchBombay

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