Phonon anomalies and possible local lattice distortions in giant magnetocapacitive CdCr2S4
- Authors
- Gnezdilov, V.; Lemmens, P.; Pashkevich, Yu G.; Payen, Ch; Choi, K. Y.; Hemberger, J.; Loidl, A.; Tsurkan, V.
- Issue Date
- Jul-2011
- Publisher
- AMER PHYSICAL SOC
- Citation
- PHYSICAL REVIEW B, v.84, no.4
- Journal Title
- PHYSICAL REVIEW B
- Volume
- 84
- Number
- 4
- URI
- https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/21408
- DOI
- 10.1103/PhysRevB.84.045106
- ISSN
- 1098-0121
1550-235X
- Abstract
- We investigate the origin of large magnetocapacitive effects in CdCr2S4 single crystals focusing on phonon anomalies in the fluctuation regime T < T* = 130 K and with the onset of ferromagnetic order T-c = 84.4 K. The observation of longitudinal optical and formerly infrared active modes for T < T-c is used to propose a loss of inversion symmetry and Cr off-centering. Further anomalies in intensity, frequency, and linewidth have an onset temperature T* that coincides with the onset of magnetocapacitive effects. The respective intensity anomalies are attributed in part to an enhanced electronic polarizability of displacements that modulate the Cr-S distance and respective hybridization. This is taken as a prerequisite to the proposed Cr off-centering. Anomalies due to the previously disregarded photodoping and resonance are analyzed comparing different excitation energies.
- Files in This Item
- There are no files associated with this item.
- Appears in
Collections - College of Natural Sciences > Department of Physics > 1. Journal Articles
![qrcode](https://api.qrserver.com/v1/create-qr-code/?size=55x55&data=https://scholarworks.bwise.kr/cau/handle/2019.sw.cau/21408)
Items in ScholarWorks are protected by copyright, with all rights reserved, unless otherwise indicated.