Surface spin-glass behavior in La[sub 2/3]Sr[sub 1/3]MnO[sub 3] nanoparticles

Zhu, T.; Shen, B. G.; Sun, J. R.; Zhao, H. W.; Zhan, W. S.
June 2001
Applied Physics Letters;6/11/2001, Vol. 78 Issue 24, p3863
Academic Journal
The low-temperature magnetic and transport properties of La[sub 2/3]Sr[sub 1/3]MnO[sub 3] nanoparticles have been investigated. It is found that a surface spin-glass behavior exists in La[sub 2/3]Sr[sub 1/3]MnO[sub 3] nanoparticles, which undergo a magnetic transition to a frozen state below 45 K. The low-temperature surface spin-glass behavior exists even at the highest field used (H=50 kOe). Moreover, the spin-glass-like transition disappears for particles above 50 nm. In addition, the suppressed low-field magnetoconductivity (LFMC) observed at low temperature for nanosized La[sub 2/3]Sr[sub 1/3]MnO[sub 3] is obviously lower than the expected upper limit of LFMC, 1/3, for polycrystalline manganites, which is proposed to arise from the higher-order tunneling through the insulating spin-glass-like surface layers. © 2001 American Institute of Physics.


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