4-8 July 2016
Kramer Law building
Africa/Johannesburg timezone
The Proceedings of SAIP2016 published on 24 December 2017
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van Hove singularities in Sr3Ru2O7

Presented by Ms. Jessica TSUEN on 5 Jul 2016 from 16:10 to 18:00
Type: Poster Presentation
Track: Track A - Division for Physics of Condensed Matter and Materials
Board #: A.073

Abstract

The metamagnetism found in the 4d transition metal oxide Sr<sub>3</sub>Ru<sub>2</sub>O<sub>7</sub> is investigated by analysing a large set of high quality angle-resolved photoelectron spectroscopy (ARPES) data on Sr<sub>3</sub>Ru<sub>2</sub>O<sub>7</sub>, that was collected at the synchrotron radiation facility BESSY in Berlin, Germany. The unusual iterant metamagnetism is theoretically predicted to be caused by van Hove singularities (vHs), which are narrow peaks in the electronic bands in the vicinity of the Fermi energy level, E<sub>F</sub>. The application of a magnetic field can cause these peaks to move and cross E<sub>F</sub>. The peaks are spin-polarised giving rise to a sharp incline in the magnetisation when they shift past E<sub>F</sub>. The ARPES data obtained was used to locate such peaks in the electronic density of states. Normalised line profiles were extracted at various values of k<sub>//</sub> and peaks close to E<sub>F</sub> were fitted to determine their energy. The histogram counting method developed by Tamai et al. [1] was used to find the position of the vHs’s as a function of energy at various locations on the Fermi surface. This method ignores matrix element effects and statistically allows for a higher resolution than the experimental one. The majority of the peaks were found within 5 meV of E<sub>F</sub>, which corresponds to the Zeeman shift at the metamagnetic transition. This supports the hypothesis that spin-polarised vHs’s underlie the metamagnetism in this system. [1] A. Tamai <i>et al.</i>, Phys. Rev. Lett. 101, 026407 (2008).

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Location: Kramer Law building
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