Figure 1

Impedance spectra (upper part) and $Z^{\prime }$-$Z^{\prime \prime }$ plots (lower part) at 220 K using three different electrodes (Ag, carbon, and Au). $Z^{\prime }$ and $Z^{\prime \prime }$ denote the real and imaginary parts of impedance, respectively. The inset figure in the $Z^{\prime }$-$Z^{\prime \prime }$ plot with the carbon electrode shows an equivalent circuit with two CR parallel circuits. The inset figure in the $Z^{\prime }$-$Z^{\prime \prime }$ plot with the Au electrode shows the enlargement of the impedance spectra.Reuse & Permissions

Figure 2

(a) Temperature dependence of capacitance ($Cs$) and resistance ($Rs$) with the Au electrode. The right-hand scale in the $Cs$ plot denotes the dielectric permittivity, $\epsilon$. (b) Arrhenius plot of relaxation frequency with the Au electrode. (c) Arrhenius plot of resistivity with the Au electrode. The resistivity measured by the impedance method, ${\rho }_{\mathrm{im}}$, and by the DC method, ${\rho }_{\mathrm{dc}}$, are plotted. The inset shows the enlargement around $T_{\mathrm{CO}}$. (d) Temperature dependences of the DC-resistances with the Ag and Au electrodes. The open circle, cross, and triangle represent the sample ($Rs$), the interfacial ($Ri$) and total ($Rs+Ri$) resistance, respectively, estimated by the impedance method with the Ag electrode at 220 K. Dashed line is a guide for the eye.Reuse & Permissions

Figure 3

Band structure of YbFO and the work function, ${\varphi }_M$, of the electrodes are shown together with the PES and the IPES spectra for YbFO [19].Reuse & Permissions

Figure 4

$Z^{\prime }$-$Z^{\prime \prime }$ plots with the carbon electrode as a function of electric field (a) and magnetic field (b) at 220 K. (c) Magnetic field dependence of resistivity, capacitance and relaxation frequency estimated from impedance spectroscopy with the Au electrode: $\Delta R=\mathbf{(}Rs(H)-Rs(0)\mathbf{)}/Rs(0)$, $\Delta C=\mathbf{(}Cs(H)-Cs(0)\mathbf{)}/Cs(0)$ and $\Delta f=\mathbf{(}fs(H)-fs(0)\mathbf{)}/fs(0)$. The bottom figure shows the magnetization hysteresis curve along the $c$-axis.Reuse & Permissions

Figure 5

Magnetic field dependence of the intensity and the half-width of half-maximum (HWHM) of $(\frac{1}{3},\frac{1}{3},-2)$ the magnetic diffraction peak. The magnetic field is applied parallel to the $c$-axis. Inset: neutron diffraction profiles along the $l$-direction at 0 Tesla (red) and 0.28 Tesla (blue). The solid lines denote the fitted results with Gaussian line shape.Reuse & Permissions