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.

中文翻译：

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CdFe2O4 的高压稳定后尖晶石相具有与其常压尖晶石相不同的磁性

α-CdFe ₂ O ₄由于共价Cd-O键而稳定了其正常的尖晶石结构，其中相邻FeO ₆八面体之间的所有连接均共享边缘，形成典型的几何受抑的Fe ³⁺磁晶格。利用高压方法，在8 GPa和1373 K下合成了具有CaFe ₂ O _{4型结构的后尖晶石相β-CdFe 2} O _{4 。新的多晶型物具有正交结构，空间群为}Pnma密度比其普通尖晶石多晶型物 (α-CdFe ₂ O ₄) 在环境条件下合成。共享边的 FeO _{6八面体沿}b轴形成锯齿形S = 5/2 自旋阶梯，在高温下主导其低维磁性，并在T _N1 = 350 K的高 Néel 温度下呈现长程反铁磁有序。此外，发现磁排序的重排发生在T _N2 = 265 K 附近，低于该温度时，两相或多个耦合的竞争会引发复杂的反铁磁行为。