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Neutron Scattering Study of Temperature-Concentration Phase Diagram of (Cu1-xMgx)GeO3

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

In doped CuGeO3 systems, such as (Cu1-xZnx)GeO3 and Cu(Ge1-xSix)O3, the spin-Peierls (SP) ordering (T xc. They thus concluded that there is a compositional phase boundary between two distinct magnetic phases. To clarify the nature of two phases, we performed neutron-scattering measurements on (Cu1-xMgx)GeO3 single crystals with various x. Analysis of the data at fixed temperature points as a function of doping concentration has revealed sudden changes of order parameters at the critical concentration xc=0.027 +- 0.001. At finite temperatures below TN, the drastic increase of the AF moment takes place at xc. The spin-Peierls order parameter delta associated with lattice dimerization shows a precipitous decrease at all temperature below Tsp. However, it goes to zero above xc only at the low temperature limit.

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H. Nakao, M. Nishi, Y. Fujii, T. Masuda, I. Tsukada, K. Uchinokura, K. Hirota, G. Shirane. 1999-05-10. Neutron Scattering Study of Temperature-Concentration Phase Diagram of (Cu1-xMgx)GeO3. https://doi.org/10.1143/jpsj.68.3662

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