Colossal permittivity and metal–semiconductor transitions in Pr₀.₆₇Ba₀.₂₂Sr₀.₁₁Mn₀.₉₇₅Ni₀.₀₂₅O₃ perovskite ceramics: optical and dielectric properties


Snini K., Masrour R., Kadim G., Ellouze M., EKİCİBİL A., Hakamy A.

Applied Physics A: Materials Science and Processing, cilt.132, sa.6, 2026 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 132 Sayı: 6
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1007/s00339-026-09737-2
  • Dergi Adı: Applied Physics A: Materials Science and Processing
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
  • Anahtar Kelimeler: Debye relaxation, Electronic and optical properties, Impedance spectroscopy, Metal–semiconductor transition; DFT, Perovskite ceramics; Colossal permittivity
  • Çukurova Üniversitesi Adresli: Evet

Özet

The dielectric and optical properties of Pr₀.₆₇Ba₀.₂₂Sr₀.₁₁Mn₀.₉₇₅Ni₀.₀₂₅O₃ were investigated using impedance spectroscopy over 80–400 K, revealing two dielectric transitions, Debye-type relaxation, and an electron plasma resonance at ~ 10⁵ Hz, along with very high permittivity (ε’ > 10⁵) and strong thermal stability. A colossal negative dielectric constant and metal–semiconductor transitions are observed, which are well supported by Density Functional Theory (DFT) results showing a plasma-like dielectric response, half-metallic behavior, and strong spin polarization at the Fermi level. Theoretical calculations further confirm that these anomalies originate from the electronic structure and interfacial (grain/grain-boundary) polarization mechanisms, ensuring good agreement with experimental observations. Overall, this combined experimental–theoretical consistency highlights the multifunctional dielectric and electronic response of the material, making it a promising candidate for energy storage devices and advanced miniaturized electronic and capacitive applications.