Gorbachev Evgeny A, Kozlyakova Ekaterina S, Alyabyeva Liudmila N, Ahmed Asmaa, Trusov Lev A
Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991, Russia.
Department of Physics, Lomonosov Moscow State University, Moscow, 119991, Russia.
Mater Horiz. 2023 May 9;10(5):1842-1847. doi: 10.1039/d3mh00089c.
The temperature behavior of the magnetic properties is crucial for the application of magnetic materials. Recently, giant room temperature coercivities (20-36 kOe) and sub-terahertz natural ferromagnetic resonance (NFMR) frequencies (160-250 GHz) were observed for single-domain M-type hexaferrites with high aluminum substitution. Herein, the temperature dependences of the magnetic properties and natural ferromagnetic resonance are studied at 5-300 K for single-domain SrCaFeAlO ( = 1.5-5.5) particles. It is shown that the samples maintain their magnetic hardness over the whole temperature range. The coercivity and NFMR frequencies have a maximum shifting to the low-temperature region with a rise in aluminum concentration. The highest coercivity of 42 kOe and the maximum NFMR frequency of 297 GHz are observed for = 5.5 at 180 K.
磁性特性的温度行为对于磁性材料的应用至关重要。最近，在高铝替代的单畴M型铁氧体中观察到了巨大的室温矫顽力（20 - 36 kOe）和亚太赫兹自然铁磁共振（NFMR）频率（160 - 250 GHz）。在此，研究了单畴SrCaFeAlO（ = 1.5 - 5.5）颗粒在5 - 300 K温度范围内磁性特性和自然铁磁共振的温度依赖性。结果表明，样品在整个温度范围内都保持其磁硬度。随着铝浓度的增加，矫顽力和NFMR频率出现最大值并向低温区域移动。在180 K时，对于 = 5.5的样品，观察到最高矫顽力为42 kOe，最大NFMR频率为297 GHz。
