Unusual Phase Transitions and Magnetoelastic Coupling in TlFe1.6Se2
Abstract
Structural, magnetic, electrical transport, and heat capacity data are reported for single crystals of TlFe{sub 1.6}Se{sub 2}. This compound crystallizes in a tetragonal structure similar to the ThCr{sub 2}Si{sub 2} structure, but with vacancies in the Fe layer. The vacancies can be ordered or disordered depending on temperature and thermal history. If the vacancies are ordered, the basal plane lattice constant increases from a to {radical}5a. Antiferromagnetic order with the Fe spins along the c axis occurs below T{sub N} {approx} 430 K, as shown by single-crystal neutron diffraction, and the magnetic structure is reported. In addition, for the vacancy-ordered crystal, two other phase transitions are found at T{sub 1} {approx} 140 K and T{sub 2} {approx} 100 K. The phase transitions at T{sub 1} and T{sub 2} are evident in heat capacity, magnetic susceptibility, resistivity data, a and c lattice parameters, and the unusual temperature dependence of the magnetic order parameter determined from neutron scattering. The phase transitions at T{sub 1} and T{sub 2} result in significant changes in the magnetic moment per iron, with 1.72(6) {micro}B observed at 300 K, 2.07(9) {micro}B at 140 K, 1.90(9) {micro}B at 115 K, and 1.31(8) {micro}B for 5 K if themore »
- Authors:
-
- ORNL
- Oak Ridge National Laboratory (ORNL)
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 1017322
- DOE Contract Number:
- DE-AC05-00OR22725
- Resource Type:
- Journal Article
- Journal Name:
- Physical Review B
- Additional Journal Information:
- Journal Volume: 83; Journal Issue: 22; Journal ID: ISSN 1098--0121
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; IRON; LATTICE PARAMETERS; MAGNETIC MOMENTS; MAGNETIC SUSCEPTIBILITY; MONOCRYSTALS; NEUTRON DIFFRACTION; NEUTRONS; ORDER PARAMETERS; SCATTERING; SPECIFIC HEAT; TEMPERATURE DEPENDENCE; TRANSPORT; VACANCIES
Citation Formats
Sales, Brian C, McGuire, Michael A, May, Andrew F, Cao, Huibo, Chakoumakos, Bryan C, and Sefat, A. S. Unusual Phase Transitions and Magnetoelastic Coupling in TlFe1.6Se2. United States: N. p., 2011.
Web. doi:10.1103/PhysRevB.83.224510.
Sales, Brian C, McGuire, Michael A, May, Andrew F, Cao, Huibo, Chakoumakos, Bryan C, & Sefat, A. S. Unusual Phase Transitions and Magnetoelastic Coupling in TlFe1.6Se2. United States. https://doi.org/10.1103/PhysRevB.83.224510
Sales, Brian C, McGuire, Michael A, May, Andrew F, Cao, Huibo, Chakoumakos, Bryan C, and Sefat, A. S. 2011.
"Unusual Phase Transitions and Magnetoelastic Coupling in TlFe1.6Se2". United States. https://doi.org/10.1103/PhysRevB.83.224510.
@article{osti_1017322,
title = {Unusual Phase Transitions and Magnetoelastic Coupling in TlFe1.6Se2},
author = {Sales, Brian C and McGuire, Michael A and May, Andrew F and Cao, Huibo and Chakoumakos, Bryan C and Sefat, A. S.},
abstractNote = {Structural, magnetic, electrical transport, and heat capacity data are reported for single crystals of TlFe{sub 1.6}Se{sub 2}. This compound crystallizes in a tetragonal structure similar to the ThCr{sub 2}Si{sub 2} structure, but with vacancies in the Fe layer. The vacancies can be ordered or disordered depending on temperature and thermal history. If the vacancies are ordered, the basal plane lattice constant increases from a to {radical}5a. Antiferromagnetic order with the Fe spins along the c axis occurs below T{sub N} {approx} 430 K, as shown by single-crystal neutron diffraction, and the magnetic structure is reported. In addition, for the vacancy-ordered crystal, two other phase transitions are found at T{sub 1} {approx} 140 K and T{sub 2} {approx} 100 K. The phase transitions at T{sub 1} and T{sub 2} are evident in heat capacity, magnetic susceptibility, resistivity data, a and c lattice parameters, and the unusual temperature dependence of the magnetic order parameter determined from neutron scattering. The phase transitions at T{sub 1} and T{sub 2} result in significant changes in the magnetic moment per iron, with 1.72(6) {micro}B observed at 300 K, 2.07(9) {micro}B at 140 K, 1.90(9) {micro}B at 115 K, and 1.31(8) {micro}B for 5 K if the same 'block checkerboard' magnetic structure is used at all temperatures. The phase transitions appear to be driven by small changes in the c lattice constant, large magnetoelastic coupling, and the localization of carriers with decreasing temperature.},
doi = {10.1103/PhysRevB.83.224510},
url = {https://www.osti.gov/biblio/1017322},
journal = {Physical Review B},
issn = {1098--0121},
number = 22,
volume = 83,
place = {United States},
year = {Sat Jan 01 00:00:00 EST 2011},
month = {Sat Jan 01 00:00:00 EST 2011}
}