华南师范大学学报（自然科学版）
華南師範大學學報（自然科學版）
화남사범대학학보（자연과학판）
JOURNAL OF SOUTH CHINA NORMAL UNIVERSITY （NATURAL SCIENCE EDITION）
2015年
4期
15-19
,共5页
PbS%声子%第一性原理计算%相转变
PbS%聲子%第一性原理計算%相轉變
PbS%성자%제일성원리계산%상전변
PbS%phonon%first-principles calculations%phase transition
采用第一性原理计算的方法研究了α／β-PbS的压力致相转变．计算了体系的键性质、电子能带结构和波恩有效电荷张量，通过分析压力下相对焓值变化得到转变压强9.6 GPa．同时，计算了声子色散曲线和声子态密度，通过比较0和9.6 GPa下的声子色散，发现在0和50 cm－1处出现了2个软模．结果表明，这2个软模在α／β-PbS的压致相变中起了重要的作用．
採用第一性原理計算的方法研究瞭α／β-PbS的壓力緻相轉變．計算瞭體繫的鍵性質、電子能帶結構和波恩有效電荷張量，通過分析壓力下相對焓值變化得到轉變壓彊9.6 GPa．同時，計算瞭聲子色散麯線和聲子態密度，通過比較0和9.6 GPa下的聲子色散，髮現在0和50 cm－1處齣現瞭2箇軟模．結果錶明，這2箇軟模在α／β-PbS的壓緻相變中起瞭重要的作用．
채용제일성원리계산적방법연구료α／β-PbS적압력치상전변．계산료체계적건성질、전자능대결구화파은유효전하장량，통과분석압력하상대함치변화득도전변압강9.6 GPa．동시，계산료성자색산곡선화성자태밀도，통과비교0화9.6 GPa하적성자색산，발현재0화50 cm－1처출현료2개연모．결과표명，저2개연모재α／β-PbS적압치상변중기료중요적작용．
In present work, first-principles calculations have been performed to study the pressure-induced phase transition of α/β-PbS.The bond properties, electronic band structures and BEC tensor are calculated.The transition pressure of 9.6 GPa is obtained through analysis of relative enthalpy with pressure.Moreover, the phonon dispersions and phonon density of states are calculated.Comparison of the phonon dispersions at 0 and 9.6 GPa reveals two soft TA phonon modes ( Eu and B1u ) , between 0 and 50 cm-1 .It is noted that these two modes play an important role in understanding the atomic devia-tions in the α-PbS and the transformation to theβ-PbS.
