title: Novel phase separation and spin dynamics of lightly doped La2-xSr2CuO4 probed by La-nuclear quadrupole resonance.
abstract: We report novel magnetic properties in the slightly hole-doped Mott-insulator La(2-x)SrxCuO4 via the La-nuclear quadrupole resonance (NQR) measurements. At x=0.018, the antiferromagnetic (AFM) La-NQR spectrum affected by internal fields comes out as the temperature decreases below T(N) approximately 150 K, whereas the nonmagnetic one persists to be observed down to a temperature T(f) approximately 20 K at which the nuclear-relaxation rate has a pronounced peak. This demonstrates that the phase separation of nonmagnetic and AFM phases occurs between T(f) and T(N). The novel phase separation is suggested as due to the partial destruction of the AFM phase caused by mobile holes via the formation of an extended spin-singlet state between Cu-derived spins and hole spins.
authors.affiliation: Department of Physical Science, Graduate School of Engineering Science, Osaka University, Toyonaka, 560-8531, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ishida
authors.forename: H
authors.initials: H
authors.lastname: Aya
authors.forename: Y
authors.initials: Y
authors.lastname: Tokunaga
authors.forename: H
authors.initials: H
authors.lastname: Kotegawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kitaoka
authors.forename: M
authors.initials: M
authors.lastname: Fujita
authors.forename: K
authors.initials: K
authors.lastname: Yamada