Abstract
Single-crystal X-ray diffraction at pressures up to 50 GPa has been employed to study the compression behavior of Sm2Ti2O7-pyrochlore. In contrast to earlier reports, we observed no pressure-induced amorphization or pressure-induced anion disorder up to 50 GPa. The experimental study has been complemented by density functional theory-based calculations. A combination of the theoretical and experimental data yields a bulk modulus of \(\approx \)185 GPa, significantly higher than a value which had been reported earlier. In comparison to earlier work, the current study provides more reliable data due to the use of neon as a pressure medium, which provides a more hydrostatic pressure than the aluminum, which had been employed as a pressure medium in the earlier studies. An analysis of the compressibility of Al\(_2\)B\(_2\)O\(_7\) pyrochlores shows an approximately linear dependence of the bulk modulus on the unit cell volume.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Aleshin E, Roy R (1962) Crystal chemistry of pyrochlore. J Am Ceram Soc 45:18–25
Gardner JS, Gingras MJP, Greedan JE (2010) Rev Mod Phys 82:53–107
Ewing RC, Weber WJ, Lian J (2004) Nuclear waste disposal—pyrochlore (A\(_2\)B\(_ 2\)O\(_7\)): nuclear waste form for the immobilization of plutonium and minor actinides. J Appl Phys 95:5949
Sanjay Kumar NR, Chandra Shekar NV, Sahu PC (2008) Pressure induced structural transformation of pyrochlore Gd\(_2\)Zr\(_2\)O\(_7\). Solid State Commun 147:357–359
Surble S, Heathman S, Raison PE et al (2010) Pressure-induced structural transition in Ln\(_2\)Zr\(_2\)O\(_7\) (Ln = Ce, Nd, Gd) pyrochlores. Phys Chem Miner 37:761–767
Zhang FX, Saxena SK (2005) Structural changes and pressure-induced amorphization in rare earth titanates RE\(_2\)Ti\(_2\)O\(_7\) (RE: Gd, Sm) with pyrochlore structure. Chem Phys Lett 413:248–251
Zhang FX, Manoun B, Saxena SK et al (2005) Structure change of pyrochlore Sm\(_2\)Ti\(_2\)O\(_7\) at high pressures. Appl Phys Lett 86:181906
Zhang FX, Lian J, Becker U et al (2007) Structural distortions and phase transformations in Sm\(_2\)Zr\(_2\)O\(_7\) pyrochlore at high pressures. Chem Phys Lett 441:216–220
Scott PR, Midgley A, Musaev O et al (2011) High-pressure synchrotron X-ray diffraction study of the pyrochlores: Ho\(_2\)Ti\(_2\)O\(_7\), Y\(_2\)Ti\(_2\)O\(_7\) and Tb\(_2\)Ti\(_2\)O\(_7\). High Pressure Res 31:219–227
Zhai S, Shan S, Yamazaki D et al (2013) Compressibility of pyrochlore-type MgZrSi\(_2\)O\(_7\) determined by in situ X-ray diffraction in a large-volume high pressure apparatus. High Pressure Res 33:1–7
Bayarjargal L, Wiehl L, Winkler B (2013) Influence of grain size, surface energy, and deviatoric stress on the pressure-induced phase transition of ZnO and AlN. High Pressure Res 33:642–651
Sickafus KE, Minervini L, Grimes RW et al (2000) Radiation tolerance of complex oxides. Science 289:748–751
Mao HK, Xu J, Bell PM (1986) Calibration of the ruby pressure gauge to 800 kbar under quasi-hydrostatic conditions. J Geophys Res 91:4673–4676
Boehler R (2006) New diamond cell for single-crystal X-ray diffraction. Rev Sci Instrum 77:115103
Liermann H, Morgenroth W, Ehnes A et al (2010) The Extreme Conditions beamline at PETRA III, DESY: possibilities to conduct time resolved monochromatic diffraction experiments in dynamic and laser heated DAC. J Phys Conf Ser 215:012029
Rothkirch A, Gatta GD, Meyer M et al (2013) Single-crystal diffraction at the Extreme Conditions beamline P02.2: procedure for collecting and analyzing high-pressure single-crystal data. J Synchrotron Radiat 20:711–720
Agilent (2013) \(CrysAlis^{Pro}\) software system, version 171.36.28. Agilent Technologies UK Ltd, Oxford
Sheldrick GM (2008) A short history of SHELX. Acta Crystallogr A64:112–122
Farrugia LJ (1999) WinGX suite for small-molecule single-crystal crystallography. J Appl Crystallogr 32:837
Clark SJ, Segall MD, Pickard CJ et al (2005) First principles methods using CASTEP. Z Kristallogr 220:567–570
Wu ZG, Cohen RE (2006) More accurate generalized gradient approximation for solids. Phys Rev B 73:235116
Knop O, Brisse F, Castelliz L et al (1969) Thermoanalytic, X-ray, neutron, infrared, and dielectric studies of A\(_2\)Ti\(_2\)O\(_7\) titanates. Can J Chem 47:971–990
Tabira Y, Withers RL (1999) The determination of an unknown oxygen atom position in rare-earth zirconate pyrochlores by a 111 systematic-row convergent-beam electron diffraction technique. Philos Mag A 79:1335–1346
Chung DH (1972) Birch’s law: why is it so good? Science 177:261–263
Panero WR, Stixrude L, Ewing RC (2004) First-principles calculation of defect-formation energies in the Y\(_2\)(Ti, Sn, Zr)\(_2\)O\(_7\) pyrochlore. Phys Rev B 70:054110
Angel RJ (2000) Equations of state. Rev Miner Geochem 41:35–60
Pruneda JM, Artacho E (2005) First-principles study of structural, elastic, and bonding properties of pyrochlores. Phys Rev B 72:085107
Feng J, Xiao B, Wan CL et al (2011) Electronic structure, mechanical properties and thermal conductivity of Ln2Zr2O7 (Ln = La, Pr, Nd, Sm, Eu and Gd) pyrochlore. Acta Mater 59:1742–1760
Acknowledgments
This work was supported by the DFG, Germany, within SPP1236 (FR-2491/2-1), the BMBF, Germany (05KS7RF1, 05K10RFA), and DESY, Germany. Portions of this research were carried out at the light source PETRA III at DESY, a member of the Helmholtz Association (HGF). We thank H.-P. Liermann (PETRA III) for support at the beamline.
Author information
Authors and Affiliations
Corresponding author
Additional information
SPECIAL TOPIC: High Pressure Physics
About this article
Cite this article
Winkler, B., Friedrich, A., Morgenroth, W. et al. Compression behavior of Sm2Ti2O7-pyrochlore up to 50 GPa: single-crystal X-ray diffraction and density functional theory calculations. Chin. Sci. Bull. 59, 5278–5282 (2014). https://doi.org/10.1007/s11434-014-0635-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11434-014-0635-5