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1996; American Physical Society; Volume: 54; Issue: 5 Linguagem: Inglês

10.1103/physrevb.54.3562

1095-3795

T. Goto, Satoru Nakajima, Masae Kikuchi, Yasuhiko Syono, Tetsuo Fukase,

Rare-earth and actinide compounds

The end member of the Tl-based high-${\mathit{T}}_{\mathit{c}}$ cuprate ${\mathrm{TlBa}}_{2}$${\mathrm{YCu}}_{2}$${\mathrm{O}}_{7}$ (Tl1212) with the zero nominal hole number has been synthesized and studied by Cu/Tl NMR. The existence of the antiferromagnetic ordering was demonstrated by the Zeeman-splitted zero-field Cu spectra. Static parameters at the Cu site such as the hyperfine field ${\mathit{H}}_{\mathrm{Cu}}$=8.62 T and the quadrupolar frequency $^{63}\ensuremath{\nu}_{\mathit{Q}}$=20.44 MHz were found to be comparable to other high-${\mathit{T}}_{\mathit{c}}$ related antiferromagnets ${\mathrm{La}}_{2}$${\mathrm{CuO}}_{4}$ and ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6}$. The relaxation rate ${\mathit{T}}_{1}^{\mathrm{\ensuremath{-}}1}$ of the Cu site of Tl1212 showed a significant deviation from the magnon theory, and was much smaller than ${\mathrm{La}}_{2}$${\mathrm{CuO}}_{4}$ and ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6}$. The scaling between the temperature dependence of Tl ${\mathit{T}}_{1}^{\mathrm{\ensuremath{-}}1}$ and Cu ${\mathit{T}}_{1}^{\mathrm{\ensuremath{-}}1}$, the ratio of which was consistently explained with the hyperfine coupling constants determined by the analysis of spectra, showed that the relaxation is dominated by the 3d spin fluctuation. A possible relation between the spin fluctuation in the antiferromagnetic phase and the superconductivity in the high-${\mathit{T}}_{\mathit{c}}$ phase is also stated. \textcopyright{} 1996 The American Physical Society.