HR: 0800h
AN: MR31B-0367    [Abstracts]
TI: Pressure-Induced Phase Transitions In Gadolinium Iron Borate
AU: * Kharlamova, S A
EM: kharlams@aps.anl.gov
AF: Advance Photon Source/Argonne National Laboratory, 9700 S.Cass Ave, Argonne, IL 60439, United States
AU: * Kharlamova, S A
EM: kharlams@aps.anl.gov
AF: Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russian Federation
AU: Struzhkin, V V
EM: Struzhkin@gl.ciw.edu
AF: Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd., N.W, Washington, DC 20015, United States
AU: Sinogeikin, S V
EM: ssinog@hpcat.aps.anl.gov
AF: Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd., N.W, Washington, DC 20015, United States
AU: Sinogeikin, S V
EM: ssinog@hpcat.aps.anl.gov
AF: HPCAT, APS/ANL, 9700 S.Cass Ave, Argonne, IL 60439, United States
AU: Gavriliuk, A G
EM: alexg@ns.hppi.troitsk.ru
AF: Institute of High-Pressure Physics,Russian Academy of Sciences, Institute of High- Pressure Physics, Troitsk, Mos 142190, Russian Federation
AU: Brown, D
EM: debrown@niu.edu
AF: Northwestern University, 1425 W. Lincoln Hwy, DeKalb, IL 60115, United States
AU: Toellner, T
EM: toellner@aps.anl.gov
AF: Advance Photon Source/Argonne National Laboratory, 9700 S.Cass Ave, Argonne, IL 60439, United States
AU: Zhao, J
EM: jzhao@aps.anl.gov
AF: Advance Photon Source/Argonne National Laboratory, 9700 S.Cass Ave, Argonne, IL 60439, United States
AU: Lerche, M
EM: lerche@aps.anl.gov
AF: Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Rd., N.W, Washington, DC 20015, United States
AU: Lyubutin, I S
EM: lyubutin@ns.crys.ras.ru
AF: Shubnikov Institute of Crystallography, Russian Academy of Sciences, 59 Leninskii Pr., Moscow, 119333, Russian Federation
AU: Ovchinnikov, S G
EM: sgo@iph.krasn.ru
AF: Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences, Akademgorodok, Krasnoyarsk, 660036, Russian Federation
AU: Alp, E E
EM: eea@aps.anl.gov
AF: Advance Photon Source/Argonne National Laboratory, 9700 S.Cass Ave, Argonne, IL 60439, United States
AU: Sturhahn, W
EM: sturhahn@aps.anl.gov
AF: Advance Photon Source/Argonne National Laboratory, 9700 S.Cass Ave, Argonne, IL 60439, United States
AB: An understanding of spin crossover (SC) dynamics is relevant to understanding of a role or participation of SC in natural systems including lower Mantle minerals, heme proteins as well as from fundamental science of view. For example, pressure-induced electronic spin transitions of Fe²⁺ and Fe³⁺ iron occur in magnesiowustite, silicate perovskite and post-perovskite which are abundant minerals in the Earth's lower mantle [1-3]. Such a SC phenomenon has recently been observed in a number of magnetic minerals FeBO₃ [4, 5], BiFeO₃ [6], Fe₂O₃ [7], and Y₃Fe₅O₁₂ [8], (La, Pr)FeO₃ [9, 10]. In those cases, iron ions are in the trivalent state Fe3+ and the high-spin-low-spin (HS–LS) crossover is manifested as the collapse of the local magnetic moment and as the transition of the antiferromagnet to a paramagnetic state. For example, in FeBO₃ at low temperatures a spin-crossover and some magnetic transitions with two triple points were found [4, 5]. Gadolinium iron borate, GdFe₃(BO₃)₄ is also a system with SEC and recently, we have reported on phase transitions induced by high pressures in this material [11, 12]. We studied the structural and magnetic behavior of GdFe⁵⁷₃(BO₃)₄ at high pressures and temperatures using a diamond anvil cell and a Synchrotron Mossbauer Spectroscopy technique. The hyperfine parameters and results obtained from the experiments are discussed. Based on our experimental data and theoretical calculation a tentative magnetic P–T phase diagram and an equation of states of GdFe⁵⁷₃(BO₃)₄ are proposed. Important features of the phase diagram are a spin crossover, insulator-semiconductor transition and possible presence of two triple points where magnetic and paramagnetic phases of the high-spin and low-spin states coexist. 1. J. Badro, J.-P. Rueff, G. Vankó, et al., Science 305, 383 (2004). 2. J. M. Jackson, W. Sturhahn, G. Shen, et al., American Mineralogist 90, 199 (2005). 3. J.Li, V.V. Struzhkin, H.-K. Mao, et al., PNAS 101, 14027 (2004). 4. I.A. Troyan, A. G. Gavrilyuk, et al., JETP Lett. 74, 24 (2001). 5. A.G. Gavriliuk, I.A. Trojan. et al., JETP 100, 688 (2005). 6. A.G. Gavriliuk, V.V. Struzhkin, et al., JETP Lett. 82, 224 (2005). 7. M.P. Pasternak, G.Kh. Rozenberg, et al., Phys. Rev. Lett. 82, 4663 (1999). 8. I.S. Lyubutin, A.G. Gavrilyuk, I. A. Troyan, et al., JETP Lett. 82, 702 (2005). 9. G.R. Hearne, M.P. Pasternak, et al., Phys. Rev. B 51, 11 495 (1995). 10. W.M. Xu, O. Naaman, G.Kh. Rozenberg, et al., Phys. Rev. B 64, 094411 (2001). 11. A.G. Gavriliuk, SA. Kharlamova, et al., JETP Lett. 80, 426 (2004). 12. A.G. Gavriliuk, S.A. Kharlamova, et al. J. Phys.: Condens. Matt. 17. 1-6 (2005)
DE: 3900 MINERAL PHYSICS
DE: 3919 Equations of state
DE: 3924 High-pressure behavior
DE: 5100 PHYSICAL PROPERTIES OF ROCKS
DE: 6045 Physics and chemistry of materials
SC: Mineral and Rock Physics [MR]
MN: 2007 Fall Meeting