Chemistry:Europium(II) titanate
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| Names | |
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| IUPAC name
Europium(II) titanate
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| Other names
Europium titante
Europium titanium oxide | |
| Identifiers | |
3D model (JSmol)
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| ChemSpider | |
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| Properties | |
| EuTiO3 | |
| Molar mass | 247.829g |
| Appearance | Black Solid |
| Hazards | |
| GHS Signal word | Warning |
| Related compounds | |
Other anions
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Europium(II) hydride Europium(II) sulfate Europium(II) sulfide |
Related compounds
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Europium barium titanate |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). | |
| Infobox references | |
Europium(II) titanate is a black mixed oxide of europium and titanium, with the chemical formula of EuTiO3. It crystallizes in the perovskite structure.[1]
History
EuTiO3 was first examined in 1966 by McGuire, Shafer, Joenk, Halperin and Pickart where the magnetic structure was examined.[2] This compound received more attention at the beginning of the 21st century (2001 to 2015) due to the low-temperature phase transition to antiferromagnetic behavior at TN = 5.5 K, which has a significant influence on the dielectric constant.[3][4][5]
Preparation
Dried Eu2O3 and Ti2O3 are mixed 1:1 and reacted in an argon atmosphere at 1400 °C:[3]
[math]\ce{ Eu2O3 + Ti2O3 -> 2EuTiO3 }[/math]
The europium is reduced and the titanium is oxidized.
Properties
Europium(II) titanate has two different crystal forms depending on the temperature. The phase transition occurs at 282 K.[3][6] The low temperature form crystallizes in the tetragonal space group I4/mcm (space group No. 140) with the lattice parameters a = 551.92(2) pm, c = 781.64(8) pm (measured at 90 K). The higher temperature form has a cubic form with Pm3m (space group No. 221) with lattice parameter a = 390.82(2) pm (measured at 300 K).[3][7] The transition temperature of the crystal structure from the low-temperature to the high-temperature phase increases with increasing pressure.[8] The compound becomes G-type antiferromagnetic below 5.5 K.[9] The specific heat capacity is 125 J·mol−1·K−1 (at 600 K).[1] 125 J·mol−1·K−1290 K is 7,6 W·m−1·K−1 and the electrical conductivity is 105 (Ω·m)−1(at 330 K).[1]
References
- ↑ 1.0 1.1 1.2 1. Muta, Hiroaki (2005). "Thermoelectric Properties of Lanthanum-Doped Europium Titanate". Materials Transactions 46 (7): 1466–1469. doi:10.2320/matertrans.46.1466.
- ↑ T. R. McGuire, M. W. Shafer, R. J. Joenk, H. A. Halperin, and S. J. Pickart (1966). "Magnetic structure of EuTiO3". Journal of Applied Physics 37 (3): 981. doi:10.1063/1.1708549. Bibcode: 1966JAP....37..981M.
- ↑ 3.0 3.1 3.2 3.3 J. Köhler, R. Dinnebier, A. Bussmann-Holder (2012). "Structural instability of EuTiO3 from X-ray powder diffraction". Phase Transitions 85 (11): 949–955. doi:10.1080/01411594.2012.709634. Bibcode: 2012PhaTr..85..949K.
- ↑ S. Kamba, D. Nuzhnyy, P. Vaněk, M. Savinov, K. Knížek, Z. Shen, E. Šantavá, K. Maca, M. Sadowski, J. Petzelt (2007). "Magnetodielectric effect and optic soft mode behaviour in quantum paraelectric EuTiO3 ceramics". Europhysics Letters 80 (2): 27002. doi:10.1209/0295-5075/80/27002. Bibcode: 2007EL.....8027002K.
- ↑ T. Katsufuji and H. Takagi (2001). "Coupling between magnetism and dielectric properties in quantum paraelectric EuTiO3". Physical Review B 64 (5): 054415-1–054415-4. doi:10.1103/PhysRevB.64.054415. Bibcode: 2001PhRvB..64e4415K.
- ↑ Bussmann-Holder, J. Köhler, R. K. Kremer, J. M. Law (2011). "Relation between structural instabilities in EuTiO3 and SrTiO3". Physical Review B 83 (21): 212102. doi:10.1103/PhysRevB.83.212102. Bibcode: 2011PhRvB..83u2102B.
- ↑ A. Bussmann-Holder, Z. Guguchia, J. Köhler, H. Keller, A. Shengelaya, A. R. Bishop (2012). "Hybrid paramagnon phonon modes at elevated temperatures in EuTiO3". New Journal of Physics 14 (9): 093013. doi:10.1088/1367-2630/14/9/093013. Bibcode: 2012NJPh...14i3013B.
- ↑ P. Parisiades, E. Liarokapis, J. Köhler, A. Bussmann-Holder, M. Mezouar (2015). "Pressure-temperature phase diagram of multiferroic EuTiO3". Physical Review B 92 (6): 064102. doi:10.1103/PhysRevB.92.064102. Bibcode: 2015PhRvB..92f4102P.
- ↑ Z. Guguchia, H. Keller, A. Bussmann-Holder, J. Köhler, R. K. Kremer (2013). "The low temperature magnetic phase diagram of EuxSr1−xTiO3". European Physical Journal B 86 (10): 409–412. doi:10.1140/epjb/e2013-40632-y. Bibcode: 2013EPJB...86..409G.
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