This report is on strain control of magnetic order parameters in 50 nm epitaxial NiFe₂O₄ (NFO) films grown on (001), (110), and (111) SrTiO₃ (STO) single-crystal substrates by pulsed laser deposition. The related in-plane strains for NFO films on (001), (110), and (111) STO substrates are found to be ―1.36 %, 1.35 %, and 1.52 %, respectively, where the lattice mismatch between film and substrate is as high as 6.7 %. Our analysis of magnetization and ferromagnetic resonance on all the NFO films reveals the presence of a uniaxial anisotropy field, which is perpendicular to the film plane. The anisotropy field decreases with the increase of strain in NFO films. Specifically, NFO films on STO (111) and STO (001) have the lowest and highest uniaxial anisotropy fileds of 1.4 kOe and 6.1 kOe, respectively. These experimental values of anisotropy field are a factor of 5–10 times smaller than those of the calculated ones due to the film defects induced by the high lattice mismatch. The studies of magnetic anisotropy of spinel ferrite films are of interest for spintronics and microwave devices.

该报告是关于在（001），（110）和（111）SrTiO ₃上生长的50 nm外延NiFe ₂ O ₄（NFO）薄膜中的磁序参数的应变控制的（STO）单晶衬底通过脉冲激光沉积。发现（001），（110）和（111）STO基板上NFO薄膜的相关面内应变分别为--1.36％，1.35％和1.52％，其中薄膜和基板之间的晶格失配为高达6.7％。我们对所有NFO薄膜的磁化和铁磁共振的分析表明，存在垂直于薄膜平面的单轴各向异性场。各向异性场随NFO薄膜应变的增加而减小。具体而言，在STO（111）和STO（001）上的NFO膜具有最低和最高的单轴各向异性场，分别为1.4 kOe和6.1 kOe。由于高晶格失配引起的薄膜缺陷，这些各向异性场的实验值比计算值小5-10倍。