High-Pressure-Stabilized Post-Spinel Phase of CdFe2O4 with Distinct Magnetism from Its Ambient-Pressure Spinel Phase

• Published in: Inorganic chemistry Vol. 62; no. 23; pp. 9139 - 9145
• Main Authors: Li, Beihong, Ye, Xubin, Wang, Xiao, Zhang, Jie, Lu, Dabiao, Zhao, Haoting, Pi, Maocai, Hu, Zhiwei, Lin, Hong-Ji, Chen, Chien-Te, Pan, Zhao, Qin, Xiaomei, Long, Youwen
• Format: Journal Article
• Language: English
• Published: American Chemical Society 12.06.2023
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.3c01002

α-CdFe2O4 stabilizes its normal spinel structure due to the covalent Cd–O bond, in which all the connections between adjacent FeO6 octahedral are edge-shared, forming a typical geometrically frustrated Fe3+ magnetic lattice. As the high-pressure methods were utilized, the post-spinel phase β-CdFe2O4 with a CaFe2O4-type structure was synthesized at 8 GPa and 1373 K. The new polymorph has an orthorhombic structure with the space group Pnma and an 11.5% higher density than that of its normal spinel polymorph (α-CdFe2O4) synthesized at ambient conditions. The edge-shared FeO6 octahedra form zigzag S = 5/2 spin ladders along the b-axis dominating its low-dimensional magnetic properties at high temperatures and a long-range antiferromagnetic ordering with a high Néel temperature of T N1 = 350 K. Further, the rearrangement of magnetic ordering was found to occur around T N2 = 265 K, below which the competition of two phases or several couplings induce complex antiferromagnetic behaviors.