Magnetocrystalline anisotropy imprinting of an antiferromagnet on an amorphous ferromagnet in FeRh/CoFeB heterostructures

Abstract

Magnetic anisotropy is a fundamental key parameter of magnetic materials that determines their applications. For ferromagnetic materials, the magnetic anisotropy can be easily detected by using conventional magnetic characterization techniques. However, due to the magnetic compensated structure in antiferromagnetic materials, synchrotron measurements, such as X-ray magnetic linear dichroism, are often needed to probe their magnetic properties. In this work, we observed an imprinted fourfold magnetic anisotropy in the amorphous ferromagnetic layer of FeRh/CoFeB heterostructures. The MOKE and ferromagnetic resonance measurements show that the easy magnetization axes of the CoFeB layer are along the FeRh〈110〉 and FeRh〈100〉 directions for the epitaxially grown FeRh layer in the antiferromagnetic and ferromagnetic states, respectively. The combined Monte Carlo simulation and first-principles calculation indicate that the fourfold magnetic anisotropy of the amorphous CoFeB layer is imprinted due to the interfacial exchange coupling between the CoFeB and FeRh moments from the magnetocrystalline anisotropy of the epitaxial FeRh layer. This observation of imprinting the magnetocrystalline anisotropy of antiferromagnetic materials on easily detected ferromagnetic materials may be applied to probe the magnetic structures of antiferromagnetic materials without using synchrotron methods.

Anisotropy and Domain Structure in Nanoscale-Thick MoS2/CoFeB Heterostructures: Implications for Transition Metal Dichalcogenide-Based Thin Films

“…The value of OR for ideal isotropic and anisotropic magnetic system is one and infinite, respectively. , The calculated value of OR for the sample M0 is 0.99. These results confirm that the CoFeB layer is magnetically isotropic in the film plane, a behavior inherent to amorphous ferromagnets where the magnetocrystalline anisotropy is insignificant due to lacking in long-range structural order. , …”

“…These results confirm that the CoFeB layer is magnetically isotropic in the film plane, a behavior inherent to amorphous ferromagnets where the magnetocrystalline anisotropy is insignificant due to lacking in long-range structural order. 24,25 On the other hand, the hysteresis loops and domain images of samples M1 and M2 (Figure 4) exhibit different behavior as ] and H c ha from these values is the measure of extent to which the anisotropy is dispersed in the system. 29 The values of and OR increase and H c ha decreases with increase in thickness of MoS 2 .…”

Enhancement of in-plane anisotropy in MoS2/CoFeB bilayers

“…The calculated value of OR for the sample M0 is 0.99. These results confirm that the CFB layer is magnetically isotropic in the film plane, a behavior inherent to amorphous ferromagnets where the magnetocrystalline anisotropy is insignificant due to lacking in long-range structural 22,23 . On the , respectively.…”

Comprehensive Law‐of‐Approach‐to‐Saturation for the Determination of Magnetic Anisotropy in Soft Magnetic Materials

“…Magnetocrystalline anisotropy, originating from spin-orbit coupling, has relevance in soft magnetic applications such as spintronic devices, magnetic field sensors and actuators, magnetic refrigeration, magnetic particle imaging, magnetic nanoparticle hyperthermia, environmental remediation, and designing highfrequency devices using soft magnetic composites. [1][2][3][4][5][6][7][8] Emerging soft magnetic composite applications involving soft magnetic Fe or its alloys and spinel ferrites are influenced by the effective magnetic anisotropy (K ) which determines the saturation field and hence the power efficiency. [9] Usually, bulk magnetic anisotropy is measured using techniques such as torque magnetometry, [10] magneto-optical Kerr effect, [11,12] and ferromagnetic resonance.…”