Crystal structure of the superconducting phases of S and Se

Compressed S and Se are studied by x-ray diffraction with synchrotron radiation up to 160 GPa. The S-IV phase is shown to have a body-centered monoclinic structure and to be stable between 83 and 150 GPa on pressure increase, where it transform to S-V with a primitive rhombohedral $\beta$-Po structure. Observation of the modulation reflections in S-IV up to 135 GPa shows that its crystal structure is incommensurately modulated, as recently reported for Se and Te. The modulated body-centered monoclinic phase of Se, Se-IV, is shown to transform to the $\beta$-Po phase Se-V at around 80 GPa. Se-V transforms to a body-centered cubic phase at 140 GPa in accordance with previous studies. Pressure dependence of the structural parameters of these high-pressure phases in S and Se are discussed in relation to their superconducting behaviour.

[1]  H. Mao,et al.  Novel chain structures in group VI elements , 2005 .

[2]  M. Hanfland,et al.  Incommensurate sulfur above 100 GPa , 2005 .

[3]  C. Hejny,et al.  Complex crystal structures of Te-II and Se-III at high pressure , 2004 .

[4]  Takahiro Yamada,et al.  Spiral chain structure of high pressure selenium − II ′ and sulfur − II from powder x-ray diffraction , 2004 .

[5]  J. Loveday,et al.  Confirmation of the incommensurate nature of Se − IV at pressures below 70 GPa , 2004 .

[6]  C. Hejny,et al.  Large structural modulations in incommensurate Te-III and Se-IV. , 2003, Physical review letters.

[7]  Takemura Kenichi,et al.  Modulated structure of solid iodine during its molecular dissociation under high pressure , 2003, Nature.

[8]  K. Nagata,et al.  X-ray structural analysis of the high-pressure phase III of tellurium , 2002 .

[9]  Yu. A. Timofeev,et al.  Superconductivity in the chalcogens up to multimegabar pressures , 2001, cond-mat/0108267.

[10]  M. McMahon,et al.  Pressure dependent incommensuration in Rb-IV. , 2001, Physical review letters.

[11]  McMahon,et al.  Ba-IV-type incommensurate crystal structure in group-V metals , 2000, Physical review letters.

[12]  J. Freericks,et al.  Comparison of structural transformations and superconductivity in compressed sulfur and selenium , 2000, cond-mat/0011449.

[13]  N. Suzuki,et al.  Structural and superconducting transition in selenium at high pressure , 2000, cond-mat/0011274.

[14]  H. Mao,et al.  Strain/order parameter coupling in the ferroelastic transition in dense SiO2 , 2000 .

[15]  D. Allan,et al.  Observation of the incommensurate barium-IV structure in strontium phase V , 2000 .

[16]  D. Allan,et al.  SELF-HOSTING INCOMMENSURATE STRUCTURE OF BARIUM IV , 1999 .

[17]  S. Rudin,et al.  Predicted Simple-Cubic Phase and Superconducting Properties for Compressed Sulfur , 1999 .

[18]  Stefano de Gironcoli,et al.  Phonon Softening and Superconductivity in Tellurium under Pressure. , 1996, Physical review letters.

[19]  M. Yao,et al.  Structure and Electronic Properties of Te–Se Mixtures under High Pressure , 1995 .

[20]  Cohen,et al.  Theory of structural, electronic, vibrational, and superconducting properties of high-pressure phases of sulfur. , 1995, Physical review. B, Condensed matter.

[21]  Goovaerts,et al.  Temperature variation of the ESR parameters of the self-trapped-electron center in PbCl2. , 1995, Physical review. B, Condensed matter.

[22]  K. Ohno,et al.  Band structure and structural stability of the high-pressure phases of the group VIb elements , 1995 .

[23]  Galli,et al.  Structural and bonding properties of solid tellurium from first-principles calculations. , 1994, Physical review. B, Condensed matter.

[24]  Luo,et al.  beta -Po phase of sulfur at 162 GPa: X-ray diffraction study to 212 GPa. , 1993, Physical review letters.

[25]  Kobayashi,et al.  Pressure-induced structural phase transition in sulfur at 83 GPa. , 1993, Physical review. B, Condensed matter.

[26]  Y. Akahama,et al.  Pressure-induced superconductivity and phase transition in selenium and tellurium , 1992 .

[27]  Krueger,et al.  Structural phase transitions and equations of state for selenium under pressures to 129 GPa. , 1992, Physical review letters.

[28]  Y. Akahama,et al.  High-pressure phase transition to β-polonium type structure in selenium , 1992 .

[29]  Y. Akahama,et al.  X-ray diffraction study on pressure-induced successive phase transition in selenium , 1992 .

[30]  Holzapfel,et al.  High-pressure structural phase transitions in tellurium. , 1988, Physical review. B, Condensed matter.

[31]  R. Haensel,et al.  European Synchrotron Radiation Facility , 1992 .

[32]  S. Tazzari.  The European Synchrotron Radiation Facility , 1985, IEEE Transactions on Nuclear Science.

[33]  O. Shimomura,et al.  Crystal Structure of the High-Pressure Phase of Tellurium , 1980 .

[34]  R. Keller,et al.  Effect of pressure on the atom positions in Se and Te , 1977 .

[35]  D. Mcwhan,et al.  Crystal Structure of Tellurium at High Pressures , 1965 .

[36]  K. Niizeki,et al.  The Structural and Electronic Properties of Sulfur under High Pressure , 1999 .

[37]  Kobayashi,et al.  Structural studies of pressure-induced phase transitions in selenium up to 150 GPa. , 1993, Physical review. B, Condensed matter.