Clarifying the origins of the low-temperature dielectric anomaly in BaZrO3

The proposed experiments will help to elucidate the origins of the dielectric anomaly in the cubic perovskite BaZrO3. This material finds use in proton-conducting fuel cells and microwave dielectrics. Recent studies demonstrated that the dielectric losses in BaZrO3 can be reduced dramatically by doping it with Nb and Ga, thus making the resulting material attractive for use in dielectric resonators for wireless communications. The observed drop in the losses has been correlated with the disappearance of the low-temperature dielectric anomalies which occur in pure BaZrO3; however, the atomistic mechanisms that underlie these anomalies remained uncertain. The proposed study aims to close this knowledge gap.

本研究拟开展的实验将有助于阐明立方钙钛矿(cubic perovskite)钛酸钡(BaZrO3)中介电异常(dielectric anomaly)的起源。该材料可应用于质子传导燃料电池(proton-conducting fuel cells)与微波电介质(microwave dielectrics)领域。近期研究表明，通过向钛酸钡中掺杂(doping)铌(Nb)与镓(Ga)，可显著降低其介电损耗(dielectric losses)，使得所得材料可适配无线通信(wireless communications)领域的介质谐振器(dielectric resonators)应用需求，具备优异应用潜力。观测到的损耗下降现象，与纯钛酸钡中出现的低温介电异常的消失存在相关性，但此类异常背后的原子尺度机制(atomistic mechanisms)仍未明确。本研究旨在填补这一学术认知空白。