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Enhancement of TC and reentrant spin-glass transition in La0.86Ca0.14Mn1-yCryO3 (y = 0, 0.1 and 0.2)

R. Suryanarayanan·T. Sudyoadsuk·T. Winotai
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Abstract

We report on the structural, frequency dependent ac susceptibility, dc magnetization and magnetoresistance (MR) measurements on polycrystalline samples of La0.86Ca0.14Mn1-yCryO3(y = 0, 0.1 and 0.2) prepared by sol-gel technique. For y = 0, a paramagnetic to ferromagnetic transition was observed at TC = 185 K. For y = 0.1, the value of TC = 200 K, an increase of 15 K and for y = 0.2, the TC = 195 K, an increase of 10 K. The imaginary part of the ac susceptibility of all the three samples shows a secondary transition at Tf < TC. For y = 0, there is no definite law to account for the frequency dependence of Tf and is attributed to a transition arising out of a canted structure. However, in the case of y = 0.1 and 0.2, the frequency dependence indicate the presence of a reentrant spin glass transition at Tf. Though all the three samples show a semi-conducting behavior between 300 and 5 K, a negative MR was observed corresponding to TC and Tf. The value of MR decreased for the Cr substituted samples.

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R. Suryanarayanan, T. Sudyoadsuk, T. Winotai. 2004-05-01. Enhancement of TC and reentrant spin-glass transition in La0.86Ca0.14Mn1-yCryO3 (y = 0, 0.1 and 0.2). https://arxiv.org/abs/cond-mat/0405012

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