TY - JOUR
T1 - Structural and electronic phase transition in Bi2Se2.1Te0.9 under pressure
AU - Tseng, Yu Chin
AU - Lin, Chih Ming
AU - Jian, Sheng Rui
AU - Le, Phuoc Huu
AU - Gospodinov, Marin M.
AU - Marinova, Vera
AU - Dimitrov, Dimitre Z.
AU - Luo, Chih-Wei
AU - Wu, Kuang Hsiung
AU - Zhang, Dong Zhou
AU - Juang, Jenh Yih
N1 - Publisher Copyright:
© 2021 Elsevier Ltd
PY - 2021/9
Y1 - 2021/9
N2 - The phase evolution of Bi2Se2.1Te0.9 driven by the applied external pressure at ambient temperature was investigated in-situ with pressure up to 30.0(2) GPa using angle-dispersive X-ray diffraction (ADXRD) and Raman scattering spectroscopy. ADXRD measurements revealed that starting from the ambient rhombohedral structure (phase I), new forms of crystal structures are found to sequentially emerge with increasing externally applied pressure. Namely a seven-fold monoclinic structure (phase II), then an eight-fold monoclinic structure (phase III), a body-centered structure (BCC, phase IV), and finally a body-centered tetragonal structure (BCT, phase V) was observed at pressures of ~10.5(3) GPa, ~18.8(1) GPa, ~23.0(1) GPa, and ~28.0(2) GPa, respectively. The Raman scattering spectroscopy consistently showed that the pressures at which the corresponding phase appeared at ~10.2(2) GPa, ~18.9(1) GPa, and ~26.1(2) GPa, respectively. Moreover, the rhombohedral phase exhibited an even more pronounced signature of electronic topological transition in low-pressure regime, as compared with those previously observed in pristine Bi2Te3 and Bi2Se3. It appears that the alloying of Bi2Se3 with Bi2Te3 has led to more profound effects in the electronic and structural properties of the resultant system than that expected from the Vegard's law.
AB - The phase evolution of Bi2Se2.1Te0.9 driven by the applied external pressure at ambient temperature was investigated in-situ with pressure up to 30.0(2) GPa using angle-dispersive X-ray diffraction (ADXRD) and Raman scattering spectroscopy. ADXRD measurements revealed that starting from the ambient rhombohedral structure (phase I), new forms of crystal structures are found to sequentially emerge with increasing externally applied pressure. Namely a seven-fold monoclinic structure (phase II), then an eight-fold monoclinic structure (phase III), a body-centered structure (BCC, phase IV), and finally a body-centered tetragonal structure (BCT, phase V) was observed at pressures of ~10.5(3) GPa, ~18.8(1) GPa, ~23.0(1) GPa, and ~28.0(2) GPa, respectively. The Raman scattering spectroscopy consistently showed that the pressures at which the corresponding phase appeared at ~10.2(2) GPa, ~18.9(1) GPa, and ~26.1(2) GPa, respectively. Moreover, the rhombohedral phase exhibited an even more pronounced signature of electronic topological transition in low-pressure regime, as compared with those previously observed in pristine Bi2Te3 and Bi2Se3. It appears that the alloying of Bi2Se3 with Bi2Te3 has led to more profound effects in the electronic and structural properties of the resultant system than that expected from the Vegard's law.
KW - Angle dispersive X-ray diffraction
KW - Pressure-induced lectronic topological transition
KW - Pressure-induced phase transition
KW - Raman scattering
KW - Topological insulators
UR - http://www.scopus.com/inward/record.url?scp=85105321786&partnerID=8YFLogxK
U2 - 10.1016/j.jpcs.2021.110123
DO - 10.1016/j.jpcs.2021.110123
M3 - Article
AN - SCOPUS:85105321786
SN - 0022-3697
VL - 156
JO - Journal of Physics and Chemistry of Solids
JF - Journal of Physics and Chemistry of Solids
M1 - 110123
ER -