Europium (II) titanate

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Crystal structure
Crystal structure of europium (II) titanate.
General
Surname Europium (II) titanate
other names
  • ETO
  • Europium (II) titanium (IV) oxide
Ratio formula EuTiO 3
Brief description

black glossy solid

External identifiers / databases
CAS number 12020-61-0
Wikidata Q86998203
properties
Molar mass 247.829 g mol −1
Physical state

firmly

density

6.15 g cm −3

safety instructions
GHS hazard labeling
no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Europium (II) titanate is a black mixed oxide of europium and titanium from the group of titanates . It crystallizes in the perovskite structure.

history

EuTiO 3 was described for the first time in 1966 by McGuire, Shafer, Joenk, Halperin and Pickart and examined for its magnetic structure. This connection got more attention in the beginning of the 21st century (2001 to 2015) due to the low temperature phase transition to antiferromagnetic behavior at T N  = 5.5 K, which has a significant influence on the dielectric constant.

Extraction and presentation

Dried Eu 2 O 3 and Ti 2 O 3 are mixed 1: 1 and reacted in an argon atmosphere at 1400 ° C.

The europium is reduced and the titanium is oxidized.

properties

Europium (II) titanate crystallizes in the tetragonal space group I 4 / mcm (space group  no.140 ) with the lattice parameters a = 551.92 (2) pm, c  = 781.64 (8) pm (measured at 90 K) and in space group Pm 3 m (space group no. 221) with the lattice parameters a  = 390.82 (2) pm (measured at 300 K). The phase transition occurs at 282 K. The transition temperature of the crystal structure from the low temperature to the high temperature phase increases with increasing pressure. The compound becomes G-type antiferromagnetic below 5.5 K. The specific heat capacity is 125 J mol −1 K −1 (at 600 K). The thermal conductivity at 290 K is 7.6 W m −1 K −1 and the electrical conductivity is 10 5  (Ω m) −1 (at 330 K). Template: room group / 140 Template: room group / 221

Individual evidence

  1. ↑ a b c d e 1. Muta, Hiroaki: Thermoelectric Properties of Lanthanum-Doped Europium Titanate . In: Materials Transactions . tape V46 , no. 7 , 2005, p. 1466–1469 , doi : 10.2320 / matertrans.46.1466 .
  2. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
  3. ^ TR McGuire, MW Shafer, RJ Joenk, HA Halperin, and SJ Pickart: Magnetic structure of EuTiO 3 . In: J. Appl. Phys. tape 37 , 1966, pp. 981 .
  4. ↑ a b c d J. Koehler, R. Dinnebier, A. Bussmann-Holder: Structural instability of EuTiO 3 from X-ray powder diffraction . In: Phase Transitions . tape 85 , no. 11 , 2012, p. 949-955 , doi : 10.1080 / 01411594.2012.709634 , arxiv : 1205.5374 .
  5. ↑ S. Kamba, D. Nuzhnyy, P. Vaněk, M. Savinov, K. Knížek, Z. Shen, E. Šantavá, K. Maca, M. Sadowski, J. Petzelt: Magnetodielectric effect and optic soft mode behavior in quantum paraelectric EuTiO 3 ceramics . In: Europhys. Lett. tape 80 , 2007, p. 27002 , doi : 10.1209 / 0295-5075 / 80/27002 .
  6. ↑ T. Katsufuji and H. Takagi : Coupling between magnetism and dielectric properties in quantum paraelectric EuTiO 3 . In: Phys. Rev. B . tape 64 , 2001, p. 054415-1-054415-4 .
  7. ^ A. Bussmann-Holder, Z. Guguchia, J. Köhler, H. Keller, A. Shengelaya, AR Bishop: Hybrid paramagnon phonon modes at elevated temperatures in EuTiO 3 . In: New Journal of Physics . tape 14 , 2012, p. 093013 , doi : 10.1088 / 1367-2630 / 14/9/093013 .
  8. ↑ Bussmann-Holder, J. Köhler, RK Kremer, JM Law: Relation between structural instabilities in EuTiO3 and SrTiO 3 . In: Phys. Rev. B . tape 83 , 2011, p. 212102 , doi : 10.1103 / PhysRevB.83.212102 .
  9. ↑ P. Parisiades, E. Liarokapis, J. Köhler, A. Bussmann-Holder, M. Mezouar: Pressure-temperature phase diagram of multiferroic EuTiO 3 . In: Phys. Rev. B . tape 92 , 2015, p. 064102 , doi : 10.1103 / PhysRevB.92.064102 .
  10. ↑ Z. Guguchia, H. Keller, A. Bussmann-Holder, J. Köhler, RK Kremer: The low temperature magnetic phase diagram of Eu x Sr 1-x TiO 3 . In: Eur. Phys. J. B . tape 86 , 2013, p. 409-412 , doi : 10.1140 / epjb / e2013-40632-y .