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Internal friction and Jahn-Teller effect in the charge-ordered La1-xCaxMnO3 (0.5<x<0.87)

R. K. Zheng·R. X. Huang·A. N. Tang·G. Li·X. G. Li·J. N. Wei·J. P. Shui·Z. Yao
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Abstract

The Jahn-Teller effect in the charge-ordered (CO) state for La1-xCaxMnO3 (0.5<x<0.87) was studied by measuring the low-temperature powder x-ray diffraction, internal friction, and shear modulus. We find that the electron-lattice interaction with the static Jahn-Teller distortion is the strongest near x=0.75 in the CO state. It was particularly observed that a crossover of the Jahn-Teller vibration mode from Q2 to Q3 near x=0.75 induces crossovers of the crystal structure from tetragonally compressed to tetragonally elongated orthorhombic, and of the magnetic structure from CE-type to C-type near x=0.75. The experimental results give strong evidence that the Jahn-Teller effect not only plays a key role in stabilizing the CO state, but also determines the magnetic and crystal structures in the CO state for La1-xCaxMnO3.

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R. K. Zheng, R. X. Huang, A. N. Tang, G. Li, X. G. Li, J. N. Wei, J. P. Shui, Z. Yao. 2002-12-01. Internal friction and Jahn-Teller effect in the charge-ordered La1-xCaxMnO3 (0.5<x<0.87). https://doi.org/10.1063/1.1519731

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