The effects of chromium substitution on the electronic and magnetic properties of CuFeO2

Ezircan P., Aslan M. S., Akyol M., Miyazaki H., Ozkendir O. M., EKİCİBİL A., ...Daha Fazla

Journal of Optoelectronics and Advanced Materials, cilt.27, sa.5-6, ss.271-280, 2025 (SCI-Expanded) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 27 Sayı: 5-6
  • Basım Tarihi: 2025
  • Dergi Adı: Journal of Optoelectronics and Advanced Materials
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex
  • Sayfa Sayıları: ss.271-280
  • Anahtar Kelimeler: Magnetic materials, Oxides, PPMS, XAFS
  • Çukurova Üniversitesi Adresli: Evet

Özet

We present a comprehensive investigation of chromium-substituted delafossite CuFe1-xCrxO2 using synchrotron X-ray diffraction (SR-XRD), X-ray absorption fine structure (XAFS) spectroscopy, and physical property measurements (10-300 K). The studied pristine CuFeO2 exhibits a stable dual-phase structure comprising dominant trigonal-rhombohedral (R-3m, 87.7 wt%) and minor hexagonal (P62/mmc, 12.3 wt%) polymorphs, which persists throughout chromium substitution. Structural analysis reveals chromium incorporation nucleates a secondary hexagonal CuCrO2 phase (P63/mmc) while preserving the host matrix's oxygen stoichiometry, attributable to stronger Fe-O versus Cr-O bonding. XAFS confirms maintained Fe3+ coordination geometry and minimal framework disruption despite Cr substitution. Remarkably, all substituted samples display soft ferromagnetism throughout 10-300 K, contrasting with pure CuFeO2's antiferromagnetic ordering below 11-14 K. This emergent ferromagnetism originates from competing exchange interactions, where introduced ferromagnetic Cr3+-O-Cr3+ pathways (J ≈ +15.4 K) coexist with native antiferromagnetic Fe3+-O-Fe3+ couplings (J ≈-8.2 K). The findings demonstrate chromium's dual role as both structural stabilizer and magnetic modifier in delafossite oxides.