Magnetic ordering in Ho-doped Bi2 Te3 topological insulator
| Autor: | G. van der Laan, S. E. Harrison, Thorsten Hesjedal, Adriana I. Figueroa, L. J. Collins-McIntyre |
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| Přispěvatelé: | University of St Andrews. School of Physics and Astronomy |
| Rok vydání: | 2016 |
| Předmět: |
Magnetic ordering
Magnetism NDAS 02 engineering and technology 01 natural sciences Condensed Matter::Materials Science Paramagnetism Antiferromagnetism Materials Science(all) 0103 physical sciences Doping Topological insulators General Materials Science 010306 general physics QC Curie–Weiss law Magnetic moment Condensed matter physics Magnetic circular dichroism Chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics QC Physics X-ray magnetic circular dichroism Condensed Matter::Strongly Correlated Electrons 0210 nano-technology Molecular beam epitaxy Néel temperature |
| Zdroj: | physica status solidi (RRL) - Rapid Research Letters. 10:467-470 |
| ISSN: | 1862-6254 |
| DOI: | 10.1002/pssr.201600061 |
| Popis: | This publication arises from research funded by the John Fell Oxford University Press (OUP) Research Fund and the Research Complex at Harwell is acknowledged for their hospitality. SEH acknowledges partial financial support from a DARPA MESO Project (No. N66001-11-1-4105) and the VPGE (Stanford University) and LCM partial financial support from EPSRC (UK) through a Doctoral Training Award. We investigate the magnetic properties of Ho-doped Bi2Te3 thin films grown by molecular beam epitaxy. Analysis of the polarized X-ray absorption spectra at the Ho M5 absorption edge gives an effective 4f magnetic moment which is ∼45% of the Hund's rule ground state value. X-ray magnetic circular dichroism (XMCD) shows no significant anisotropy, which suggests that the reduced spin moment is not due to the crystal field effects, but rather the presence of non-magnetic or antiferromagnetic Ho sites. Extrapolating the temperature dependence of the XMCD measured in total electron yield and fluorescence yield mode in a field of 7 T gives a Curie-Weiss temperature of θ CW ≈ -30 K, which suggests antiferromagnetic ordering, in contrast to the paramagnetic behavior observed with SQUID magnetometry. From the anomaly of the XMCD signal at low temperatures, a Néel temperature TN between 10 K and 25 K is estimated. Postprint |
| Databáze: | OpenAIRE |
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