Experimental observation of purely resistive effect in epsilon-near-zero transition metal perovskite

• Published in: Acta materialia 2024-03, Vol.266, p.119704, Article 119704
• Main Authors: Wei, Zaixin, Zhao, Lanling, Wang, Zhongyang, Xu, Ciqun, Zhang, Yan, Liu, Yao, Gao, Weibo, Fan, Runhua
• Format: Article
• Language: English
• Subjects: Electrical property; Epsilon-near-zero; Impedance property; Transition metal perovskite
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2024.119704

The epsilon-near-zero (ENZ) properties of nanomaterials provide a promising paradigm for the development of next-generation nanoscale electronic devices, especially in 6 G communication systems. However, realizing ENZ in the radio frequency (RF) domain remains a challenge due to the scarcity of materials. Here, a strategy is proposed to exploit the intrinsic excitation of polarons and delocalized electrons to modify the carrier dynamics in transition metal perovskite for tailored dielectric response in the RF domain. Polarons and delocalized electrons are introduced into the material through lattice distortion and exchange mechanisms between magnetic atoms, and are precisely governed. The tunable kHz-band ENZ is realized in La0.90Ba0.10CoO3 and described using the Debye-Drude model. Importantly, the purely resistive effect is experimentally observed under ENZ condition, manifesting as near-zero reactance and phase angle, which is attributed to the inductor-capacitor resonance through equivalent circuit analysis. These findings provide a new avenue for implementing ENZ at RF domain and identify transition metal perovskites as ENZ candidates. We engineer metal oxide perovskites to achieve an ENZ material whose dielectric response is tailored for the RF frequency range, which is achieved by a weighted combination of polarization and plasma oscillations. The kHz-band ENZ behavior is thereby realized. [Display omitted]