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Critical neutron scattering study of the compositional phase transition in Mg-doped CuGeO3

M. Nishi·H. Nakao·Y. Fujii·T. Masuda·K. Uchinokura·G. Shirane
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Abstract

Cu1-xMgxGeO3 undergoes a first-order phase transition at a critical concentration xc between an antiferromagnetic (AF) state on dimerized lattice (D-AF) and an AF Neel state on undistorted uniform lattice (U-AF). Previous magnetic susceptibility measurements showed xc = 0.023 while a recent neutron scattering study reported xc = 0.027 +- 0.001. The present critical scattering due to antiferromagnetic fluctuations near the superlattice reflection (0,1,1/2) unambiguously determines xc = 0.028 +- 0.001 at TN = 3.4 ~ 4 K. Also at T = 1.3 K, the phase boundary was determined as xc = 0.028 +- 0.001 by observation of a jump of an effective magnetic moment across xc.

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M. Nishi, H. Nakao, Y. Fujii, T. Masuda, K. Uchinokura, G. Shirane. 2000-07-27. Critical neutron scattering study of the compositional phase transition in Mg-doped CuGeO3. https://doi.org/10.1143/jpsj.69.3186

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