Monoclinic KBiFe2O5 exhibits three key features: (i) unconventional dual bandgap (1.69 eV and 2.17 eV) from Fe-O orbital contributions for broadband photovoltaics; (ii) multiferroic coupling comprising G-type antiferromagnetic order (Tc~832 K) with spin-canted weak ferromagnetism and ferroelectricity driven by stereochemically active Bi3+ lone pairs; (iii) first comprehensive thermal characterization revealing standard molar entropy (297.59 J K−1 mol−1), enthalpy, and significant magnetocaloric effects near 832 K, establishing potential for solid-state refrigeration.
- Chao Su
- Huiya Tang
- Shuiyuan Chen
