TY - JOUR
T1 - Compositional Control and Optimization of Molecular Beam Epitaxial Growth of (Sb2Te3)1- x(MnSb2Te4)xMagnetic Topological Insulators
AU - Levy, Ido
AU - Forrester, Candice
AU - Deng, Haiming
AU - Roldan-Gutierrez, Manuel
AU - McCartney, Martha
AU - Smith, David J.
AU - Testelin, Christophe
AU - Krusin-Elbaum, Lia
AU - Tamargo, Maria C.
N1 - Funding Information:
This work was supported by NSF Grant No. DMR-2011738 (PAQM). Partial support is also acknowledged from NSF Grant Nos. HRD-1547830 (CREST IDEALS) and HRD-2112550 (Phase II CREST IDEALS). The authors would like to acknowledge the Nanofabrication Facility of the CUNY Advanced Science Research Center (ASRC) for instrument use and scientific and technical assistance.
Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/5/4
Y1 - 2022/5/4
N2 - Magnetic topological insulators such as MnBi2Te4 and MnSb2Te4 are promising hosts of novel physical phenomena such as the quantum anomalous Hall effect and intrinsic axion insulator state, both potentially important for the implementation in topological spintronics and error-free quantum computing. In the bulk, the materials are antiferromagnetic, but appropriate stacking with nonmagnetic layers or excess Mn in the crystal lattice can induce a net ferromagnetic alignment. Accurate control of the materials growth is thus essential to optimize the magnetic properties. In this work, we report a detailed investigation of the growth of (Sb2Te3)1-x(MnSb2Te4)x layers with varying Mn content by molecular beam epitaxy. The Mn flux fraction provided during growth controls the percent of MnSb2Te4 that is formed in the resulting layers by a self-assembly process. Highly crystalline layers with compositions varying between Sb2Te3 (x = 0) and MnSb2Te4 (x = 1) were obtained. The results show that Mn is incorporated as a structural component to form septuple layers (SLs) of MnSb2Te4. Excess Mn was observed in the samples, suggesting that it is incorporated as antisite defects into both Sb2Te3 and MnSb2Te4. Two modifications of the growth conditions were implemented to enhance the incorporation of Mn as a structural element to form MnSb2Te4 SLs: annealing of a thin portion of the layer at the beginning of growth (preannealing step) and increasing the growth temperature. Both result in a larger percent of MnSb2Te4 SLs for similar Mn flux fractions during growth, increasing the control of the growth and providing insight into the Mn incorporation process.
AB - Magnetic topological insulators such as MnBi2Te4 and MnSb2Te4 are promising hosts of novel physical phenomena such as the quantum anomalous Hall effect and intrinsic axion insulator state, both potentially important for the implementation in topological spintronics and error-free quantum computing. In the bulk, the materials are antiferromagnetic, but appropriate stacking with nonmagnetic layers or excess Mn in the crystal lattice can induce a net ferromagnetic alignment. Accurate control of the materials growth is thus essential to optimize the magnetic properties. In this work, we report a detailed investigation of the growth of (Sb2Te3)1-x(MnSb2Te4)x layers with varying Mn content by molecular beam epitaxy. The Mn flux fraction provided during growth controls the percent of MnSb2Te4 that is formed in the resulting layers by a self-assembly process. Highly crystalline layers with compositions varying between Sb2Te3 (x = 0) and MnSb2Te4 (x = 1) were obtained. The results show that Mn is incorporated as a structural component to form septuple layers (SLs) of MnSb2Te4. Excess Mn was observed in the samples, suggesting that it is incorporated as antisite defects into both Sb2Te3 and MnSb2Te4. Two modifications of the growth conditions were implemented to enhance the incorporation of Mn as a structural element to form MnSb2Te4 SLs: annealing of a thin portion of the layer at the beginning of growth (preannealing step) and increasing the growth temperature. Both result in a larger percent of MnSb2Te4 SLs for similar Mn flux fractions during growth, increasing the control of the growth and providing insight into the Mn incorporation process.
UR - http://www.scopus.com/inward/record.url?scp=85127905746&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85127905746&partnerID=8YFLogxK
U2 - 10.1021/acs.cgd.1c01453
DO - 10.1021/acs.cgd.1c01453
M3 - Article
AN - SCOPUS:85127905746
SN - 1528-7483
VL - 22
SP - 3007
EP - 3015
JO - Crystal Growth and Design
JF - Crystal Growth and Design
IS - 5
ER -