Versatile Intense Triple-Axis Spectrometer
VERITAS | HB-1A | HFIR
VERITAS is a fixed-incident-energy triple-axis spectrometer that is most beneficial to the condensed matter physics and materials science research communities. It is an excellent instrument for measuring low-lying magnetic excitations in solids and for studying structural and magnetic phase transitions in bulk materials as well as thin films. Due to its versatility, this instrument can be used for parametric studies with a variety of sample environments to provide complete control of thermodynamic variables such as temperature, magnetic field, pressure, and electric field. VERITAS is a particularly good instrument for studying materials with weak scattering signals, including millimeter-size single crystals, powders, and thin films. The use of energy analysis in thin film studies is a key capability which enables the desired signal to be separated from the massive substrate background.
The following examples highlight the typical capabilities of HB-1A:
- Study structural and magnetic phase transitions in bulk materials
- Lu X., Gretarsson H., Zhang R., Liu X., Luo H., Tian W., Laver M., Yamani Z., Kim Y.-J., Nevidomskyy A. H., Si Q., Dai P., "Avoided quantum criticality and magnetoelastic coupling in BaFe2-xNixAs2 ", Physical Review Letters 110, 257001 (2013).
- Dhital C., Khadka S., Yamani Z., Cruz C. dela, Hogan T. C., Disseler S. M., Pokharel M., Lukas K. C., Tian W., Opeil C. P., Wang Z., Wilson S. D., "Spin ordering and electronic texture in the bilayer iridate Sr3Ir2O7", Physical Review B: Condensed Matter and Materials Physics 86, 100401 (2012).
- Pratt D. K., Kim M. G., Kreyssig A., Lee Y. B., Tucker G. S., Thaler A., Tian W., Zarestky J. L., Bud'ko S. L., Canfield P. C., Harmon B. N., Goldman A. I., McQueeney R. J., "Incommensurate spin-density wave order in electron-doped BaFe2As2 superconductors", Physical Review Letters 106, 257001 (2011).
- Study structural and magnetic phase transitions in thin film and nanoparticle materials
- Wang W., Zhao J., Wang W., Gai Z., Balke N., Chi M., Lee H. N., Tian W., Zhu L., Cheng X., Keavney D. J., Yi J., Ward T. Z., Snijders P. C., Christen H. M., Wu W., Shen J., Xu X., "Room-temperature multiferroic hexagonal LuFeO3 films", Physical Review Letters 110, 237601 (2013).
- Siemons W., MacDougall G. J., Aczel A. A., Zarestky J. L., Biegalski M. D., Liang S., Dagotto E., Nagler S. E., Christen H. M., "Strain dependence of transition temperatures and structural symmetry of BiFeO3 within the tetragonal-like structure", Applied Physics Letters 101, 212901 (2012).
- Santos T. S., Kirby B. J., Kumar S., May S. J., Borchers J. A., Maranville B. B., Zarestky J., te Velthuis S. G. E., van den Brink J., Bhattacharya A., "Delta doping of ferromagnetism in antiferromagnetic manganite superlattices", Physical Review Letters 107, 167202 (2011).
- Study low-lying magnetic excitations
- Wang C. H., Lumsden M. D., Fishman R. S., Ehlers G., Hong T., Tian W., Cao H., Podlesnyak A., Dunmars C., Schlueter J. A., Manson J. L., Christianson A. D., "Magnetic properties of the S=1/2 quasisquare lattice antiferromagnet CuF2(H2O)2(pyz) (pyz = pyrazine) investigated by neutron scattering", Physical Review B: Condensed Matter and Materials Physics 86, 064439 (2012).
- Tian W., Li J. Y., Lynn J. W., Zarestky J. L., Vaknin D., "Spin dynamics in the magnetoelectric effect compound LiCoPO4", Physical Review B 78, 184429 (2008).
- Study high-temperature phonons using neutron energy gain
- Ma J., Delaire O., May A. F., Carlton C. E., McGuire M. A., VanBebber L. H., Abernathy D. L., Ehlers G., Hong T., Huq A., Tian W., Keppens V. M., Shao-Horn Y., Sales B. C., "Glass-like phonon scattering from a spontaneous nanostructure in AgSbTe2", Nature Nanotechnology, (2013).
- Cai Ling., Toulouse Jean., Luo Haosu, and Tian Wei, “Anisotropic and competing phonon coupling in relaxor ferroelectric (Na1/2Bi1/2)TiO3 near high temperature phase transition”, submitted to Physical Review B
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