Temperature dependence under pressure of the kinetics of crystallization of bulk amorphous selenium

Mohan, Murali; Singh, Anil K.

doi:10.1080/13642819308219318

Cited by 5 publications

(3 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This observation is dicult to be interpreted in terms of the previous model that high pressure retards the crystallization process by suppressing the eect on the atomic diusivity, because no long-range atomic diusion is involved in the polymorphous crystallization process of aSe. Mohan et al [16] attributed the observed decrease of the crystallization rate of a-Se at high pressures to the increase of the activation energy for viscous¯ow. However, it was mentioned that the pressure dependence of the glass transition temperature dT g /dP is about 130 K/GPa [18].…”

Section: Discussionmentioning

confidence: 99%

“…Moreover, the volume dierence between a-Se and t-Se is relatively large (about 13%), which facilitates the demonstration of the pressure eect on the transformation kinetics. Mohan et al [16] have investigated the pressure (0.28±0.69 GPa)± temperature (382±409 K) dependence of the crystallization kinetics of a-Se to t-Se by isothermal annealing an a-Se sample under pressure. In the present work, we systematically studied the crystallization kinetics of a-Se under pressure ranging from ambient to 1.0 GPa by continuously heating a-Se in a cylinder pressure vessel.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Pressure effect on polymorphous crystallization kinetics in amorphous selenium

1998

Acta Materialia

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Pressure effect on polymorphous crystallization kinetics in amorphous selenium

1998

Acta Materialia

View full text Add to dashboard Cite

“…随后围绕非晶硒是否存在压致相变开展了较多的实验研究, 发现常温、～10 GPa压力下非晶硒发生压致结晶, 转变为t-Se相 [17,18] . Singh等 [6] 采用活塞圆筒测量了非晶硒的压缩性质, 认为常温下5 GPa以内压缩率没有不连续变化. He等 [19] 测量了高压下非晶硒的声速, 发现横波和纵波的走时及声速随压力变化曲线存在相似的拐点, 拐点的压力值在2.0-2.5 GPa范围, 推测非晶硒可能存在压致多形态转变.…”

Section: 引言unclassified

Mechanism of rapid compression-induced melt crystallization in selenium

Wang,

et al. 2021

Acta Phys. Sin.

View full text Add to dashboard Cite

Amorphous selenium (Se) can be easily prepared by quenching the melt, which indicates that the Se possesses the good glass-forming ability. However, crystallization occurs after rapidly compressing the melt within about 20 ms. In this work, we investigate the mechanism of rapid compression-induced crystallization from Se melt. Compressing Se melt experiments are carried out at the following temperatures: 513, 523 and 533 K. The melt is rapidly compressed under 2.4 GPa for about 20 ms. Different holding times, i.e. 0, 30, 60 min after solidification are adopted. The samples are quenched to room temperature and then unloaded to ambient pressure. The X-ray diffraction analysis of the recovered sample indicates that the crystallization product is the t-Se. It is found that with the prolongation of holding time, the grain size increases due to the continuous aggregation growth of crystal grains. By comparing with the isothermal crystallization products of amorphous Se and ultrafine Se powder, it is suggested that the rapid compression-induced solidification product should be t-Se crystalline. The speculation that the solidification product is amorphous Se and it crystallizes in the cooling process does not hold true. The amorphous Se cannot be prepared through the rapid compression process on a millisecond scale. It is related to the thermal stability of amorphous Se under high pressure. It is reported that the dependence of crystallization temperature Tx on pressure i.e. dTx/dP for amorphous Se is about 40–50 K/GPa in a range of 0.1 MPa–1 GPa. However, the Tx of amorphous Se is almost constant in a range of 2–6 GPa. It means that the thermal stability of amorphous Se against crystallization does not increase with increasing pressure after 2 GPa. In this work, the temperature of 513–533 K in the experiments is higher than the Tx of amorphous Se. Therefore, the t-Se crystal is the stable phase and amorphous Se is unstable. The Se melt tends to crystallize in the supercooled liquid state after rapid compression. It is interesting to investigate the mechanism of dTx/dP curve discontinuous change at around 2 GPa in the future. Both the Se melt after rapid compression and the amorphous Se before crystallization are in supercooled liquid state. We speculate that high pressure may result in the microstructure transition in supercooled liquid state Se.

show abstract

Pressure effect on thermal-induced crystallization of amorphous selenium up to 5.5 GPa

Liu

Zhang

et al. 2014

Solid State Communications

View full text Add to dashboard Cite

Temperature dependence under pressure of the kinetics of crystallization of bulk amorphous selenium

Cited by 5 publications

References 23 publications

Pressure effect on polymorphous crystallization kinetics in amorphous selenium

Pressure effect on polymorphous crystallization kinetics in amorphous selenium

Mechanism of rapid compression-induced melt crystallization in selenium

Pressure effect on thermal-induced crystallization of amorphous selenium up to 5.5 GPa

Contact Info

Product

Resources

About