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

N. Khan; A. Midya; P. Mandal; D. Prabhakaran

doi:10.1063/1.4804333

paper

Critical exponents and irreversibility lines of La $_{0.9}$ Sr $_{0.1}$ CoO $_{3}$ single crystal

arXiv:1301.4120 · doi:10.1063/1.4804333

Abstract

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

11 pages, 7 figures

References in corpus (6)

Cited by in corpus (1)

Memory effects and magnetic relaxation in single-crystalline La $_{0.9}$ Sr $_{0.1}$ CoO $_{3}$

Critical exponents and irreversibility lines of La0.9​Sr0.1​CoO3​ single crystal

Abstract

References in corpus (6)

Cited by in corpus (1)

Critical exponents and irreversibility lines of La $_{0.9}$ Sr $_{0.1}$ CoO $_{3}$ single crystal