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arXiv · 0706.0602

Effect of Mn substitution by Ga on the optical properties of a metallic manganite

A. Nucara·P. Maselli·M. Del Bufalo·M. Cestelli Guidi·J. Garcia·P. Orgiani·L. Maritato·P. Calvani
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Abstract

In a metallic manganite like La(2/3)Sr(1/3)MnO(3), the substitution of Mn(+3) by Ga(+3) dilutes the ferromagnetic order and locally cancels the Jahn-Teller distortion, without heavily affecting the crystal structure. One can thus follow the changes in the charge dynamics induced by Ga, until the ferro-metallic manganite is turned into an insulator. Here this phenomenon is studied in detail through the infrared reflectivity of five samples of La(2/3)Sr(1/3)Mn(1-x)Ga(x)O(3), with x increasing from 0 to 0.30 and for 50 < T < 320 K. A simple model which links the measured optical parameters to the magnetization M(x, T) well describes the behavior of the plasma frequency, the scattering rate, and the mid-infrared absorption along the metal-to-insulator transition.

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A. Nucara, P. Maselli, M. Del Bufalo, M. Cestelli Guidi, J. Garcia, P. Orgiani, L. Maritato, P. Calvani. 2007-06-05. Effect of Mn substitution by Ga on the optical properties of a metallic manganite. https://doi.org/10.1103/physrevb.77.064431

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