| 压力下钒发生相变的第一性原理计算 |
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| 引用本文： | 王家佳,陈爱华,李瑜璞,于金,吴三械.压力下钒发生相变的第一性原理计算[J].东南大学学报(自然科学版),2009,39(5). |
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| 作者姓名： | 王家佳 陈爱华 李瑜璞 于金 吴三械 |
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| 作者单位： | 1. 东南大学材料科学与工程学院,南京,211189;东南大学江苏省先进金属材料高技术研究重点实验室,南京,211189
2. 南京大学化学化工学院,南京,210008 |
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| 基金项目： | 国家自然科学基金资助项目，江苏省博士后基金资助项目 |
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| 摘 要： | 利用投影缀加波方法对金属钒加压至400 GPa左右的结构相变过程进行了第一性原理研究. 计算了相变中的热力学转变压力和失稳转变压力, 并对相变前后的电子性质进行了研究. 结果表明: 钒在低压下为体心立方结构, 随着压力增大转变为菱方结构, 压力继续增大最后又重新转变为体心立方结构. 热力学计算得到的BCC→rhu(α>109.47°)→rhl(α<109.47°)→BCC三次转变压力分别为27,104和310 GPa. 利用剪切弹性常数C44计算得到的2次失稳压力分别为52和255 GPa. 能带计算表明, 在加压过程中高对称点Γ处靠近费米能级的能带由低压下的非电子占据态变为高压下的占据态, 而费米能级以上的电子态密度计算可见明显的s,p-d带间电子迁移现象.
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| 关 键 词： | 钒 压致相变 第一性原理 相变压力 电子结构 |
First principles calculation of phase transition of vanadium under pressure |
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| Wang Jiajia,Chen Aihua,Li Yupu,Yu Jin,Wu Sanxie.First principles calculation of phase transition of vanadium under pressure[J].Journal of Southeast University(Natural Science Edition),2009,39(5). |
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| Authors: | Wang Jiajia Chen Aihua Li Yupu Yu Jin Wu Sanxie |
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| Institution: | Wang Jiajia1,2 Chen Aihua1,2 Li Yupu1,2 Yu Jin1,2 Wu Sanxie3(1School of Materials Science , Engineering,Southeast University,Nanjing 211189,China)(2Jiangsu Key Laboratory of Advanced Metallic Materials,China)(3College of Chemistry , Chemical Engineering,Nanjing University,Nanjing 210008,China) |
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| Abstract: | Recent experiment revealed a new structural phase transition in vanadium at high pressure. Here the whole phase transition process under pressure up to 400 GPa was investigated from first principles calculation with projector augmented wave (PAW) method. The results show that body -centered cubic (BCC) vanadium firstly makes a transition to rhombohedral(rh) structure under pressure, and with increasing pressure, it transforms back to BCC again. Three thermodynamic phase transition pressures of BCC→rh~u(α > 109. 47°) →rh~1( α < 109. 47°) →BCC are 27, 104 and 310 GPa, respectively. Two instability pressures obtained by calculation of shear elastic constant C_(44) at different pressures are 52 and 255 GPa. Electronic properties calculation reveals that bands near Γ point gradually move below the Fermi level and become occupied condition. Calculation of decomposed density of states at Fermi level presents obvious s, p-d electrons transition among bands. |
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| Keywords: | vanadium pressure-induced phase transition first principles phase transition pressure electronic structure |
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