Antiferromagnetic resonance study of sodalite loaded with sodium by multi-frequency ESR

作者：Kashiwagi T; Nakano T; Hanazawa A; Nozue Y; Hagiwara M^*

来源：Journal of Physics and Chemistry of Solids, 2010, 71(4): 544-547.

DOI：10.1016/j.jpcs.2009.12.032

• Magnetic materials
• Microporous materials
• Nanostructures
• Magnetic properties
• Phase transitions

We have carried out electron spin resonance (ESR) measurements on powder samples of sodalite loaded with Na at several frequencies between 9.7 and 35 GHz and at temperatures between 1.5 and 60 K. The ESR absorption spectrum below a Neel temperature T(N) turns into an asymmetric spectrum with a long tail at low fields from a symmetric one above T(N). The line shape of the spectra below T(N) is analyzed by a powder pattern simulation of the antiferromagnetic resonance spectra with easy-plane anisotropy. The calculated line shape reproduces the experimental one considerably well by assuming a Gaussian distribution of the zero-field energy gap. We have evaluated a small anisotropy field of about 2 x 10(-4) T by using the exchange coupling constant calculated from the Weiss and the Ne! temperatures. This result indicates that the sodalite loaded with Na is quite an ideal Heisenberg antiferromagnet as expected from the s-electron character of Na clusters and the cubic arrangement of nano-spaces in the sodalite.

• 出版日期2010-4