Critical exponents and irreversibility lines of La$_{0.9}$Sr$_{0.1}$CoO$_3$ single crystal

摘要: We have studied the dynamic and static critical behavior of spin glass transition in insulating La$_{0.9}$Sr$_{0.1}$CoO$_3$ single crystal by ac susceptibility dc magnetization measurements vicinity its freezing temperature ($T_f$). The scaling analysis frequency dependence data yields characteristic time constant $\tau_{0}$=1.6(9)$\times10^{-12}$ s, exponent $z\nu$=9.5(2), a factor $K$=$\Delta$$T_{f}/T_{f}$($\Delta$$log$$f$)=0.017, indicating that sample enters into canonical spin-glass phase below $T_{f}$=34.8(2) K. non-linear $T_{f}$ through hypothesis exponents $\beta$=0.89(1) $\gamma$=2.9(1), which match well with observed for known three-dimensional (3D) Heisenberg glasses. From longitudinal component zero-field-cooled field-cooled measurement we constructed $H-T$ diagram represents field evolution two temperatures: upper one, $T_{w}(H)$, indicates onset uniform external $H$, while lower $T_{s}(H)$, marks strong irreversibility frozen state. low $T_{s}(H)$ follows line suggested d'Almeida-Thouless model glass, whereas $T_{w}(H)$ exhibits reentrant maximum at nonzero above it Gabay-Toulouse (GT) is glass. re-entrant GT resembles predicted theoretically $n$-component vector glasses presence uniaxial anisotropy field.