Effect of High Pressure on the Dielectric Properties of SrMoO₄

Abstract

In situ impedance measurement and first-principles calculations have been performed to investigate the effect of high pressure (up to 35.5 GPa) on the dielectric properties of SrMoO4. It is found that the carrier transport process is dominated by the grains, and the variation in resistance under compression is related to the change in activation energy. The relative permittivity of the tetragonal phase of SrMoO4 is stable below 7.0 GPa and has stable electrical storage capacity as well. However, the electron localization around O atoms in the monoclinic phase is enhanced with the increase in pressure, resulting in a decreased relative permittivity. A typical dielectric loss by electronic conduction of SrMoO4 is also presented. After unloading pressure, the dielectric loss of the low-frequency region is significantly reduced. Besides, the dielectric performance of SrMoO4 is effectively optimized by pressure. This study will provide a theoretical and experimental basis for the design and modification of other related ABO4-type materials for dielectric devices.

Application of impedance spectroscopy in exploring electrical properties of dielectric materials under high pressure

“…Alkaline molybdate materials with the chemical formula of AMoO 4 (A = Ba, Ca, Sr) are possible candidates for microwave dielectric devices due to their low dielectric constant and high-quality factor [86,87]. In-situ impedance measurements were employed to investigate the dielectric property of AMoO 4 under pressure [88][89][90]. Although the pressure-induced phase transition paths of the three compounds are similar (from tetragonal to monoclinic) [91][92][93], there are still some differences in their electrical transport and dielectric properties under pressure.…”

Pressure effects on the electrical transport properties of benzene

“…The negative d E /d P manifests that the energy required for relaxation decreases with increasing pressure. 22,23 These results clearly demonstrate that the electrical transportation properties of benzene can be promoted by high pressure and presages the metallization under ultra-high pressure.…”

“…The relaxation frequency represents the charge and discharge rate during the dipole oscillation, and the relaxation activation energy ( E ) is the energy that activates the resonance. By linearly fitting the ln f – P curve with the Arrhenius relationship, 22 the pressure dependence of the activation energy (d E /d P ) is calculated to be −3.26, −5.19, −1.06 meV GPa −1 for the Pbca , P 4 3 2 1 2, P 2 1 / c phases, respectively. The negative d E /d P manifests that the energy required for relaxation decreases with increasing pressure.…”

Pressure effects on the ionic transport properties of LiNH2

“…3(e) represents the characteristic rate of the dipole oscillation, and the relaxation activation energy ( E ) is the energy that can activate the dipole oscillation. By linearly fitting the ln f – P curve with the Arrhenius relationship, 23 the pressure dependence of activation energy (d E /d P ) is calculated to be 4.14 meV GPa −1 for a tetragonal phase below 12.5 GPa and −1.73, 1.19 meV GPa −1 for a monoclinic phase, respectively, below and above 20.0 GPa. The positive d E /d P manifests that the energy required for excitation increases at higher pressures and the dipole oscillation becomes slow.…”