该研究测量了磁性材料CdCrO的红外声子谱随温度变化的情况。在低温的反铁磁相中，三重简并的Cr声子软化并分裂为单重和双重模式，这与四角形畸变相关，以缓解晶格的几何挫败。声子分裂的原因并非简单的键长变化，而是由于磁有序状态导致的力常数变化。分裂现象与ZnCrO中的观察结果相反，且其大小揭示了磁-声子耦合的强度，该强度小于ZnCrO的情况。
摘要：
The infrared phonon spectrum of the spinel CdCrOis measured as a function of temperature from 6 to 300 K. The triply degenerate Cr phonons soften in the paramagnetic phase as temperature is lowered below 100 K and then split into a singlet and doublet in the low temperature antiferromagnetic phase, which is tetragonally distorted to relieve the geometric frustration in the pyrochlore lattice of ions. The phonon splitting is inconsistent with the simple increase (decrease) in the force constants due to decreasing (increasing) bond lengths in the tetragonal phase. Rather they correspond to changes in the force constants due to the magnetic order in the antiferromagnetic state. The phonon splitting in this system is opposite of that observed earlier in ZnCrOas predicted by theory. The magnitude of the splitting gives a measure of the spin-phonon coupling strength, which is smaller than in the case of ZnCrO.
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