轨道诱导Peierls相变材料MgTi2O4的电子自旋共振研究

用变温电子自旋共振手段，对轨道诱导Peierls相变MgTi2O4体系进行了研究。研究发现，轨道诱导Peierls相变所伴随的自旋二聚相变对ESR谱产生了影响。在相变温度以上，MgTi2O4的磁性为顺磁行为。而在相变温度以下，ESR谱显示MgTi2O4的磁性偏离了顺磁行为。对ESR谱线的参数拟合结果显示，MgTi2O4在发生轨道诱导Peierls相变时，自旋耦合作用逐渐增强。这说明:自旋耦合作用的增强很有可能是导致相变的一个重要的因素。

Electron Spin Resonance Study of the Orbitally-Induced Peierls State in MgTi2O4

The MgTi2O4, which exhibits an orbitally-induced Peierls phase transition, has been investigated by the Electron Spin Resonance device. It is found that the spin-dimerization transition, which accompanies the orbitally-induced Peierls phase transition, has effect on the temperature dependence of the ESR spectra. Above the phase transition temperature, MgTi2O4 exhibits a paramagnetic behavior. Below the phase transition temperature, the ESR spectra shows that the magnetic behavior deviates the paramagnetic behavior. The fitting of ESR spectra indicates that the spin coupling in enhanced when the orbitally-induced Peierls phase transition occurs. The ESR results suggest that the enhancement of the spin coupling may be one of the factors causing the occurrence of the phase transition.