Atypical magnetism in Pt/MgO/FeCoB/Pt waveguide structure by exchanging the order of MgO and FeCoB layers

被引：4

作者：

Jamal M.S. ^{[1
]}

Singh S. ^{[2
]}

Dev A.S. ^{[1
]}

Gupta N. ^{[3
]}

Gupta P. ^{[3
,4
]}

Gupta M. ^{[1
]}

Leupold O. ^{[5
]}

Sergueev I. ^{[5
]}

Reddy V.R. ^{[1
]}

Kumar D. ^{[1
]}

机构：

[1] UGC-DAE Consortium for Scientific Research, Indore

[2] IIT Hyderabad, Academic Block B-216, Kandi, Sangareddy

[3] Raja Ramanna Centre for Advanced Technology, Indore

[4] HBNI, Training School Complex, Mumbai, Anushakti Nagar

[5] Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg

来源：

Acta Materialia | 2023年 / 257卷

关键词：

FeCoB/MgO bilayer; Grazing incident nuclear resonance scattering; Magnetic anisotropy; X-ray standing wave;

D O I：

10.1016/j.actamat.2023.119150

中图分类号：

学科分类号：

摘要：

Interfaces in FeCoB/MgO/FeCoB magnetic tunnel junction play a vital role in controlling their magnetic and transport properties for various applications in spintronics and magnetic recording media. In this work, interface structures of a few nm thick FeCoB layers in FeCoB/MgO and MgO/FeCoB bilayers are comprehensively studied using x-ray standing waves (XSW) generated by depositing bilayers between Pt waveguide structures. High interface selectivity of nuclear resonance scattering (NRS) under the XSW technique allowed to measure structure and magnetism at the two interfaces, namely FeCoB-on-MgO and MgO-on-FeCoB, yielding an interesting result that electron density and hyperfine fields are not symmetric at both interfaces. The formation of a high-density FeCoB layer at the MgO/FeCoB (FeCoB-on-MgO) interface with an increased hyperfine field (∼34.65 T) is attributed to the increasing volume of FeCo at the interface due to boron diffusion from 57FeCoB to the MgO layer. Furthermore, it caused unusual angular-dependent magnetic properties in MgO/FeCoB bilayer, whereas FeCoB/MgO is magnetically isotropic. In contrast to the literature, where the unusual angular dependent in FeCoB based system is explained in terms of in-plane magnetic anisotropy, present findings attributed the same to the interlayer exchange coupling between bulk and interface layer within the FeCoB layer. © 2023 Acta Materialia Inc.

引用

共 59 条

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