α－Fe_2O_3超微粒的集体磁激发现象  

COLLECTIVE MAGNETIC EXCITATIONS IN α-Fe_2O_3 ULTRAFINE PARTICLES

作　　者：李海波[1] 宫杰[1] 陈岗[1] 幸志明[1] 余瑞璜[1] 

机构地区：[1]吉林大学,四平师范学院

出　　处：《金属学报》1996年第4期409-412,共4页Acta Metallurgica Sinica

基　　金：中国科学院金属研究所快速凝固非平衡合金国家重点实验室;吉林省科学技术委员会资助

摘　　要：利用沉淀法制备了α－Ｆｅ_２Ｏ_３超微粒。在室温下测量三个不同粒度样品的Ｍｓｓｂａｕｅｒ谱，并在室温到８０Ｋ的温度范围内测量了其中一个样品的Ｍｓｓｂａｕｅｒ谱。结果表明，由于集体磁激发现象的存在，随颗粒尺寸和环境温度的改变，样品的内磁场发生了明显变化。通过对集体磁激发现象的研究，得到了不同颗粒尺寸的α－Ｆｅ_２Ｏ_３超微粒的磁各向异性能常数．?Fe_2O_3 ultrafine particles were prepared by precipitation method. The Mssbauer spectra of three samples with various grain size were measured at room temperature and one of them in temperature range from 295 to 80 K. The results indicate that the internal magnetic field has varied obviously with the change of grain size and environment temperature mainly due to collective magnetic excitations. The magnetic anisotropy constants of the samples with various grain size were obtained by the studies of collective magnetic excitations.

关 键 词：超微粒 集体磁激发 磁性 各向异性 

分 类 号：TM271.014[一般工业技术—材料科学与工程]