Effect of the Non-Magnetic Ion Doping on the Magnetic Behavior of MgCr2O4

作者：Fuxi Zhou, Zheng He, Donger Cheng, Han Ge, Wenjing Zhang, Xiao Wang, Pengfei Zhou, Wanju Luo, Zhengdong Fu, Xinzhi Liu, Liusuo Wu, Lunhua He, Yanchun Zhao, Erxi Feng · 发表于：Magnetism · 年份：2025 · DOI：10.3390/magnetism5030019 · 被引用次数：3 · 研究领域：Advanced Condensed Matter Physics、Multiferroics and related materials、Magnetic Properties and Synthesis of Ferrites

Geometrically frustrated magnets exhibit exotic excitations due to competing interactions between spins. The spinel compound MgCr2O4, a three-dimensional Heisenberg antiferromagnet, hosts both spin-wave and spin-resonance modes, but the origin of its resonant excitations remains debated. Suppressing magnetic order via non-magnetic doping can help isolate these modes in neutron scattering studies. We synthesized Ga3+ and Cd2+-doped MgCr2O4 via solid-state reaction and analyzed their structure and magnetism. Ga3+ doping (0–20%) causes anomalous lattice shrinkage due to site disorder from Ga3+ occupying both Mg2+ and Cr3+ sites. Magnetically, Ga3+ doping drives the system from the antiferromagnetic order to a spin-glass state, fully suppressing magnetic ordering at 20% doping. In contrast, Cd2+ replaces only Mg2+, expanding the lattice and meantime inducing strong spin-glass behavior. At 10% Cd2+, long-range antiferromagnetic order is entirely suppressed. Thus, 10% Cd-doped MgCr2O4 offers an ideal platform to study the resonant magnetic excitations without any spin-wave interference.