Cu nuclear quadrupole resonance study of the spin-Peierls compound Cu1-xMgxGeO3: A possibility of precursory dimerization

Article

关键词: UNIFORM-ANTIFERROMAGNETIC PHASES;    LONG-RANGE ORDER;    SI-DOPED CUGEO3;    NEUTRON-SCATTERING;    ELECTRONIC-STATE;    CU-63,CU-65 NMR;    SYSTEM CUGEO3;    LATTICE RELAXATION;    SINGLE-CRYSTALS;    SOLITON LATTICE;   

DOI  :  10.1103/PhysRevB.65.100406

来源: SCIE

【 摘 要 】

We report on a zero-field Cu-63 nuclear quadrupole resonance (NQR) study of nonmagnetic Mg impurity substituted Cu1-xMgxGeO3 (single crystals; the spin-Peierls transition temperature T(sp)similar to14, 13.5, and 11 K for x=0, 0.0043, and 0.020) in a temperature range from 4.2 to 250 K. We found that below T*similar to77 K, Cu NQR spectra are broadened and nonexponential Cu nuclear spin-lattice relaxation increases for undoped and more remarkably for Mg-doped samples. The results indicate that random lattice distortion and impurity-induced spins appear below T*, which we associate with a precursor of the spin-Peierls transition. Conventional magnetic critical slowing down does not appear down to 4.2 K below T-sp.

【 授权许可】

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