Dynamics of iron atoms across the pressure-induced Invar transition in Pd{sub 3}Fe.
- X-Ray Science Division
The {sup 57}Fe phonon partial density of states (PDOS) in L1{sub 2}-ordered Pd{sub 3}Fe was studied at high pressures by nuclear resonant inelastic x-ray scattering (NRIXS) measurements and density functional theory (DFT) calculations. The NRIXS spectra showed that the stiffening of the {sup 57}Fe PDOS with decreasing volume was slower from 12 to 24 GPa owing to the pressure-induced Invar transition in Pd{sub 3}Fe, with a change from a high-moment ferromagnetic (FM) state to a low-moment (LM) state observed by nuclear forward scattering. Force constants obtained from fitting to a Born-von Karman model showed a relative softening of the first-nearest-neighbor (1NN) Fe-Pd longitudinal force constants at the magnetic transition. For the FM low-pressure state, the DFT calculations gave a PDOS and 1NN longitudinal force constants in good agreement with experiment, but discrepancies for the high-pressure LM state suggest the presence of short-range magnetic order.
- Research Organization:
- Argonne National Lab. (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC); National Science Foundation (NSF)
- DOE Contract Number:
- DE-AC02-06CH11357
- OSTI ID:
- 1015956
- Report Number(s):
- ANL/XSD/JA-70000; TRN: US201112%%88
- Journal Information:
- Phys. Rev. B, Vol. 83, Issue Apr. 2011
- Country of Publication:
- United States
- Language:
- ENGLISH
Similar Records
Nuclear resonant x-ray spectroscopy of (Mg,Fe)SiO{sub 3} orthoenstatites.
Influence of interfaces on the phonon density of states of nanoscale metallic multilayers: Phonon confinement and localization