Effect of Annealing Temperature on the Structural and the Electrical Transport Properties of La₂NiMnO₆ Nanoparticles

Abstract

The effect of annealing temperatures on the structural and the electrical transport properties of La2NiMnO6 nanoparticles is investigated in detail. The grain size, grain boundary and the antisite disorder (ASD) are affected by the annealing temperature during the preparative conditions of annealing. The HRTEM image indicates that the average grain size increases with annealing temperature providing a platform for explanation of the transport data. Both I−V and dIdV−V measurements show that the electrical conduction is non‐Ohmic and characterized by a voltage V0true(ATtrue), known as the onset voltage, which scales with the Ohmic conductance Σ0true(ATtrue) as V0true(ATtrue)∼Σ0true(Ttrue)xAT, xAT being the onset exponent having negative values in both cases. AT refers to the fact that Σ0true(ATtrue) is changed by the annealing temperature (AT). V0true(ATtrue) depends strongly on the grain size and grain boundaries and decreases with the increase in annealing temperature. The negative value of xAT is physically understood from the concept of inter‐granular tunneling effect. This non‐Ohmic conduction, onset voltage V0true(ATtrue) and onset exponent xAT are qualitatively explained by considering the conduction through both the ordered and disordered regions and by applying Glazman–Matveev model. The transport data are systematically analyzed within the framework of scaling formalism.

Redox-Guided Synthesis of Au–V2O5–MnO2 Nanoflower Composites with Enhanced Electrical Conductance for Supercapacitor Applications

“…In this measurement, the range of applied dc voltage was 0–14 V because it could not exceed 14 V in order to be fed into the input terminal of the operational amplifier (OP-AMP) OP07 because the maximum input voltage for OP07 is ±14 V. There were two reasons to choose frequency f = 33 Hz: at this low frequency, the frequency response of the samples was essentially flat, and pickup from a 50-Hz-line frequency or its higher harmonics did not take place. Circuit elements for this ac modulation basically consisted of two OP-AMP (OP07) . In the adder circuit, an OP07(1) operational amplifier added ac signal V ac (= V 0 sin ω t ) taken from the LIA with dc voltage V dc , obtained from the dc voltage source (Yokogawa 7651).…”

“…Circuit elements for this ac modulation basically consisted of two OP-AMP (OP07). 30 In the adder circuit, 30 an OP07(1) operational amplifier added ac signal V ac (=V 0 sin ωt) taken from the LIA with dc voltage V dc , obtained from the dc voltage source (Yokogawa 7651). From the output of the adder circuit, the combined ac and dc voltages (V ac + V dc ) were applied to the sample connected with an inverting terminal of the second OP-AMP.…”