High-pressure behavior of amorphous selenium from ultrasonic measurements and Raman spectroscopy
- National Key Laboratory for Shock Wave and Detonation Physics Research, Institute of Fluid Physics, Chinese Academy of Engineering Physics, Mianyang 621900 (China)
- State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012 (China)
- School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031 (China)
The high-pressure behavior of melt-quenched amorphous selenium (a-Se) has been investigated via ultrasonic measurements and Raman scattering at room temperature. The ultrasonic measurements were conducted on a-Se in a multi-anvil apparatus with two different sample assemblies at pressures of up to 4.5 and 4.8 GPa. We discovered that similar kinks occur in the slopes of the pressure dependence characteristics of the travel time and the sound velocity in both shear and longitudinal waves in the 2.0–2.5 GPa range. These kinks are independent of the sample assemblies, indicating an intrinsic transformation of the a-Se. Additionally, we deduced the pressure-volume relationship of a-Se from the sound velocity characteristics using the Birch–Murnaghan equation of state, and the results agreed well with those of previous reports. In situ high-pressure Raman scattering measurements of a-Se were conducted in a diamond anvil cell with an 830 nm excitation line up to a pressure of 4.3 GPa. We found that the characteristic band of a-Se at ∼250 cm{sup −1} experienced a smooth shift to a lower frequency with pressure, but a sharp slope change in the band intensity versus pressure occurred near 2.5 GPa. The results of X-ray diffraction and differential scanning calorimetry measurements indicate that the samples remain in their amorphous states after decompression. Thus, we proposed that the abnormal compression behavior of a-Se in the 2.0–2.5 GPa range can be attributed to pressure-induced local atomic reconfiguration, implying an amorphous-amorphous transition of the elementary selenium.
- OSTI ID:
- 22303941
- Journal Information:
- Applied Physics Letters, Vol. 105, Issue 1; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AMORPHOUS STATE
CALORIMETRY
COMPRESSION
DIAMONDS
EQUATIONS OF STATE
EQUIPMENT
EXCITATION
PRESSURE DEPENDENCE
PRESSURE RANGE GIGA PA
RAMAN EFFECT
RAMAN SPECTROSCOPY
SELENIUM
SOUND WAVES
TEMPERATURE RANGE 0273-0400 K
TRANSFORMATIONS
X-RAY DIFFRACTION