Temperature-dependent J-E characteristics and electrical conductivity in LRS. (a) Linear relation between current density and electric field at temperature ranging from 25 to 150°C in LRS. (b) Temperature dependence (diamond with black and white shades) of the electrical conductivity in LRS. The inset graph shows the location of Fermi level in ohmic conduction. σ, Electrical conductivity; EC, conduction band edge; T, absolute temperature; K1, Boltzmann's constant; Ea, activation energy; EV, valence band edge.