Effects of temperature and pressure on phonons in FeSi_(1-x)Al_x
Abstract
The effects of temperature and pressure on phonons in B20 compounds FeSi_(1−x)Al_x were measured using inelastic neutron scattering and nuclear-resonant inelastic x-ray scattering. The effect of hole doping through Al substitution is compared to results of alloying with Co (electron doping) in Fe_(1−x)Co_xSi. While the temperature dependence of phonons in FeSi is highly anomalous, doping with either type of carriers leads to a recovery of the normal quasiharmonic behavior. Density functional theory (DFT) computations of the electronic band structure and phonons were performed. The anomaly in the temperature dependence of the phonons in undoped FeSi was related to the narrow band gap, and its sensitivity to the effect of thermal disordering by phonons. On the other hand, the pressure dependence of phonons at room temperature in undoped FeSi follows the quasiharmonic behavior and is well reproduced by the DFT calculations.
Additional Information
© 2013 American Physical Society. Received 30 March 2013; revised manuscript received 1 May 2013; published 31 May 2013. O.D. and B.S. acknowledge funding from the US Department of Energy (DOE), Office of Basic Energy Sciences, Materials Sciences and Engineering Division. J.M. was supported by the US DOE, Office of Basic Energy Sciences, as part of an Energy Frontier Research Center, DOE Grant DESC0001299. The phonon modeling work was sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US DOE. The Research at Oak Ridge National Laboratory's Spallation Neutron Source was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, DOE. Use of the HPCAT facility was supported by DOE-BES, DOE-NNSA (CDAC), NSF, DOD TACOM, and the W. M. Keck Foundation. Use of the APS was supported by DOE-BES, under Contract No. DE-AC02-06CH11357.Attached Files
Published - PhysRevB.87.184304.pdf
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Additional details
- Eprint ID
- 39429
- Resolver ID
- CaltechAUTHORS:20130718-073418523
- DE-SC0001299
- Department of Energy (DOE)
- Oak Ridge National Laboratory
- National Nuclear Security Administration
- NSF
- W. M. Keck Foundation
- DE-AC02-06CH11357
- Department of Energy (DOE)
- Created
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2013-08-05Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field