Figure 1

Real part of the dielectric permittivity $\left[{\epsilon }^{\prime }(\omega ,T)\right]$ versus temperature $\left(T\right)$ patterns for $\mathrm{La}\mathrm{Mn}{\mathrm{O}}_3$ single crystal; the anomaly at $T_N$ is conspicuous. There appears to be a slight frequency dependence of the nature of the anomaly. (a) the ${\epsilon }^{\prime }(\omega ,T)$ versus $T$ pattern over a wide temperature range; the anomalies at $T_N$ and Jahn-Teller transition point $T_{\mathit{JT}}$ are conspicuous. The region near $T_{\mathit{JT}}$ is fitted (solid line) by a local polar domain (defect-lattice) model. (b) The polarization $\left(P\right)$ versus electric field $\left(E\right)$ loop and the variation of capacitance with time $\left(t\right)$ at $77\mathrm{K}$.Reuse & Permissions

Figure 2

(Color online) (a) Real (solid line) and imaginary (dotted line) parts of the impedance $\left[Z\left(\omega \right)\right]$ spectra at different temperatures. In real part, the corresponding temperatures are (from top) 90, 95, 98, 102, 107, 112, 115, 122, 125, 130, 134, 137, 140, 144, 147, 150, 160, 165, 170, 175, 180, and $200\mathrm{K}$, and in imaginary part, the corresponding temperatures are (from bottom) 90, 95, 98, 102, 107, 112, and $115\mathrm{K}$. [(b) and (c)] Complex-plane impedance patterns below, close, and above $T_N$; the solid lines have been obtained from Eq. (1) and the equivalent circuit with circuit elements is shown in the inset.Reuse & Permissions

Figure 3

The variation of equivalent circuit parameters, (a) frequency-independent resistance $\left(R_N\right)$ and (b) capacitance $\left(C_0\right)$, as well as (c) the Kohlrausch exponent $\beta$ and (d) the dielectric relaxation time $\left({\tau }_0\right)$ with temperature across the transition point $T_N$. Dashed lines are guides for the eye.Reuse & Permissions