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论文类型：期刊论文

发表时间：2010-01-01

发表刊物：JOURNAL OF SOLID STATE CHEMISTRY

收录刊物：SCIE、EI

卷号：183

期号：1

页面范围：136-143

ISSN号：0022-4596

关键字：Intermetallics; Band structures; Elastic properties; Heats of formation; First-principle calculations

摘要：The structural properties, elastic properties, heats of formation, electronic structures, and densities of states of 20 intermetallic compounds in the Ca-X (X=Si, Ge, Sn, Pb) systems have been systematically investigated by using first-principle calculations. Our computational results indicated that with increasing atomic weight of X, the bulk modulus of Ca-X intermetallic compounds decreases gradually. It was also found that Ca(36)Sn(23) and CaPb are mechanically unstable phases. Results on the electronic energy band and densities of states also indicated that Ca(3)Si(4) is an indirect band gap semiconductor with a band gap of 0.598 eV, and Ca(2)Si, Ca(2)Ge, Ca(2)Sn, and Ca(2)Pb are direct band gap semiconductors with band gaps of 0.324, 0.265, 0.06, and 0.07 eV, respectively. In addition, it is found that the absolute values of heats of formation for all Ca-X intermetallics are larger than 30 kJ/mol atom. (C) 2009 Elsevier Inc. All rights reserved.