High-pressure magnetic properties and P-T phase diagram of iron borate
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The high-pressure magnetic states of iron borate 57FeBO3 single-crystal and powder samples have been investigated in diamond anvil cells by nuclear forward scattering (NFS) of synchrotron radiation at different temperatures. In the low-pressure (0 < P < 46 GPa) antiferromagnetic phase, an increase of the Neél temperature from 350 to 595 K induced by pressure was found. At pressures 46–49 GPa, a transition from the antiferromagnetic to a new magnetic state with a weak magnetic moment (magnetic collapse) was discovered. It is attributed to the electronic transition in Fe3+ ions from the high-spin 3d5 (S = 5/2, 6A1g) to the low-spin (S = 1/2, 2T2g) state (spin crossover) due to the insulator-semiconductor-type transition with extensive suppression of strong d-d electron correlations. At low temperatures, NFS spectra of the high-pressure phase indicate magnetic correlations in the low-spin system with a magnetic ordering temperature of about 50 K. A tentative magnetic P-T phase diagram of FeBO3 is proposed. An important feature of this diagram is the presence of two triple points where magnetic and paramagnetic phases of the high-spin and low-spin states coexist.
KeywordsPhase Diagram Magnetic State Electronic Transition Synchrotron Radiation Triple Point
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- 3.R. Wolfe, A. J. Kurtzig, and R. C. LeCraw, J. Appl. Phys. 41, 1218 (1970).Google Scholar
- 4.M. Eibschuts, L. Pfeiffer, and J. W. Nielsen, J. Appl. Phys. 41, 1276 (1970).Google Scholar
- 5.M. P. Petrov, G. A. Smolenskii, A. P. Pagurt, et al., Fiz. Tverd. Tela (Leningrad) 14, 109 (1972) [Sov. Phys. Solid State 14, 87 (1972)].Google Scholar
- 8.R. Ruffer and A. I. Chumakov, Hyperfine Interact. 97/98, 589 (1996).Google Scholar
- 9.G. V. Smirnov, Hyperfine Interact. 123/124, 31 (1999).Google Scholar
- 19.S. G. Ovchinnikov and V. N. Zabluda, JETP 98, 135 (2004).Google Scholar
- 22.É. A. Nagaev, Physics of Magnetic Semiconductors (Nauka, Moscow, 1979) [in Russian].Google Scholar
- 24.P. Fulde, Electron Correlations in Molecules and Solids (Springer, Berlin, 1991), Springer Ser. Solid-State Sci., Vol. 100.Google Scholar