Considering the improvement of electronics regarding high frequency and miniaturization, SrM hexaferrites need to exhibit high anisotropy field H_a, high remanence ratio M_r/M_s, and low ferromagnetic resonance linewidth ΔH to create microwave devices and equipment with planarisation, miniaturisation, and high frequencies. The key to achieving self-biased microwave devices with high-frequency is to simultaneously achieve high H_a, high M_r/M_s, and low ΔH. However, it is hard to meet these requirements. In this study, Sr_0.4La_0.3Ca_0.3Fe_11.85Al_1.0Co_0.15O₁₉ was used to study the effect of different doping amounts of Bi₂O₃ on its magnetic characteristics, micromorphology and FMR linewidth. With the increase of Bi₂O₃ doping, the grain size of the sample gradually increased, and the uniformity of the grain size gradually decreased. When the Bi₂O₃ doping amount x increased from 0 to 1.2 wt%, the 4πM_s and 4πM_r values increased and the coercivity displayed the opposite tendency. The samples showed great uniaxial anisotropy. The magnetocrystalline anisotropy field H_a shows a trend of initially decreased and then increased. When x = 1.0 wt%, H_a reaches the maximum value of 28.9 kOe. At this time, the ferromagnetic resonance linewidth ΔH of the sample is 1578 Oe. The theory of IGA was adopted to divide the FMR linewidth into two parts ΔH_a and ΔH_p. Accroding to the results, ΔH_a takes the bigger proportion of linewidth. However, the change in ΔH_p is not negligible. When x = 1.0 wt%, the sample showed its best performance (4πM_s = 3412 Gs, 4πM_r = 2905 Gs, H_c = 2649 Oe, M_r/M_s = 85.1%, large H_a = 28.864 kOe, and ΔH = 1578 Oe). The SrM ferrite materials provided in this study can potentially be used in the microwave engineering, high-frequency, and self-biased devices.

考虑到电子器件在高频和小型化方面的改进，SrM 六铁氧体需要表现出高各向异性场H _a、高剩磁比M _r / M _s和低铁磁共振线宽 Δ H以创建具有平面化、小型化和高频。实现高频自偏置微波器件的关键是同时实现高H _a、高M _r / M _s和低Δ H。但是，要满足这些要求是很困难的。在本研究中，Sr _0.4 La_0.3 Ca _0.3 Fe _11.85 Al _1.0 Co _0.15 O ₁₉用于研究不同Bi ₂ O ₃掺杂量对其磁特性、微观形貌和FMR线宽的影响。随着Bi ₂ O ₃掺杂量的增加，样品的晶粒尺寸逐渐增大，晶粒尺寸的均匀性逐渐降低。当 Bi ₂ O ₃掺杂量x从 0 增加到 1.2 wt% 时，4π M _s和 4π M _r值增加，矫顽力显示出相反的趋势。样品显示出很大的单轴各向异性。晶磁各向异性场H _a呈现先减小后增大的趋势。当x  = 1.0 wt% 时，H _a达到最大值 28.9 kOe。此时，样品的铁磁共振线宽ΔH为1578 Oe。采用IGA理论将FMR线宽分为ΔH _a和Δ H _p两部分。根据结果​​，Δ H _a占线宽的比例较大。然而，ΔH _p的变化不容忽视。当x  = 1.0 wt%时，样品表现出最佳性能（4π M _s  = 3412 Gs，4π M _r  = 2905 Gs，H _c  = 2649 Oe，M _r / M _s  = 85.1%，大H _a  = 28.864 kOe，和 Δ H  = 1578 Oe）。本研究中提供的 SrM 铁氧体材料可用于微波工程、高频和自偏置器件。