Antiferromagnetic long-range order in Cu1-xZnxGeO3 with extremely low Zn concentration

Article

关键词: SPIN-PEIERLS TRANSITION;    DOPED CUGEO3;    PHASE;    SYSTEM;    CU;   

DOI  :  10.1103/PhysRevB.58.R575

来源: SCIE

【 摘 要 】

We have measured the magnetic susceptibilities of single crystals of Cu1-xZnxGeO3 with extremely low Zn concentration (x) lower than x=5 x 10(-3) at very low temperatures to investigate the spin-Peierls and antiferromagnetic transitions. The results show that the undoped CuGeO3 has no antiferromagnetic phase down to 12 mK and there exists an antiferromagnetic long-range order with the easy axis alone the c axis for x down to 1.12(2)x10(-3). The minimum observed Neel temperature was 0;0285 K for the x=1.12(2)x10(-3) sample. From the concentration dependence of the Neel temperature it is concluded that there is no critical concentration for the occurrence of the antiferromagnetic long-range order. This indicates that the dimerization sustains the coherence of the antiferromagnetic phase of the spin polarization in impurity-doped systems and is consistent with the theory of the impurity-doped spin-Peierls system. The temperature dependence of the susceptibilities at T>T-N of all samples indicates that the magnetic correlations between localized spins are enhanced by a relatively large interchain interaction of CuGeO3. [S0163-1829(98)51826-7].

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