Disentangling magnetism and phonons in magnetostrictive CoFe2O4:

CoFe2O4 is a highly magnetostrictive material with a very high magnetic ordering temperature near 900 K. Preliminary triple-axis work has found sharp acoustic phonons, but energy broadened excitations which we suspect are magnetic. We propose to use MERLIN to map out the magnetic response over many Brillouin zones and also to establish the energy dependence. This work will be done in parallel with work investigating the phonons to determine the origin of the high magnetostrictive response.

钴铁氧体（CoFe₂O₄）是一种高磁致伸缩材料，其磁有序温度极高，接近900开尔文。前期开展的三轴谱学实验已观测到尖锐的声学声子，但同时存在能量展宽的激发态，我们推测该激发态为磁激发。本研究拟利用MERLIN测绘多个布里渊区（Brillouin zone）内的磁响应分布，并明确其能量依赖关系。本工作将与探究声子特性的研究同步推进，以厘清该材料高磁致伸缩效应的起源。