Dresden 2017 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 74: Group IV: Si/Ge/SiC

HL 74.5: Vortrag

Donnerstag, 23. März 2017, 13:00–13:15, POT 06

Defect-induced magnetism in SiC probed by nuclear magnetic resonance — •Zhitao Zhang^1,2, Daryna Dmytriieva^2,3, Sebastian Molatta^2,3, J. Wosnitza^2,3, Yutian Wang¹, Manfred Helm^1,3, Shengqiang Zhou¹, and Hannes Kühne² — ¹Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden, Germany — ²Hochfeld-Magnetlabor Dresden (HLD-EMFL), Helmholtz-Zentrum Dresden-Rossendorf, D-01314 Dresden, Germany — ³TU Dresden, D-01062 Dresden, Germany

We give evidence for intrinsic, defect-induced bulk paramagnetism in SiC by means of ¹³C and ²⁹Si nuclear magnetic resonance (NMR) spectroscopy. The temperature dependence of the internal dipole-field distribution, probed by the spin part of the NMR Knight shift and the spectral linewidth, follows a Curie law and scales very well with the macroscopic DC susceptibility. In order to quantitatively analyze the NMR spectra, a microscopic model based on dipole-dipole interactions was developed. The very good agreement between these simulations and the NMR data establishes a direct relation between the frequency distribution of the spectral intensity and the corresponding real-space volumes of nuclear spins. The presented approach by NMR can be applied to a variety of similar materials and, thus, opens a new avenue for the microscopic exploration and exploitation of diluted bulk magnetism in semiconductors.