(武漢理工大學(xué) 材料復(fù)合新技術(shù)國家重點實驗室，
武漢 430070)
摘 要: 采用離散變分Xα量子化學(xué)計算方法， 研究了二硼化鈦的化學(xué)鍵和價電子結(jié)構(gòu)特征，并闡述了TiB2陶瓷晶體結(jié)構(gòu)、 電子結(jié)構(gòu)與其力學(xué)性能和電性能之間的關(guān)系。 結(jié)果表明： TiB2晶體結(jié)構(gòu)中包含了Ti2+與B-混合鍵、 B-與B-間的σ鍵以及B-2pπ電子構(gòu)成的離域大π鍵； TiB2晶體的導(dǎo)帶和價帶電子主要是由Ti3d和B2p軌道的價電子構(gòu)成， 這些價電子通過離域大π鍵在電流的作用下可在TiB2晶體中遷移。
關(guān)鍵字: 二硼化鈦； 價電子結(jié)構(gòu)； 量子化學(xué)
titanium diboride crystal
FU Zheng-yi, YUAN Run-zhang
（State Key Lab of Advanced Technology for Materials Synthesis and Processing, Wuhan University of Technology, Wuhan 430070, China）
Abstract:Based on its structures of chemical bonds and valence electrons, titanium diboride has special physical and chemical properties. The chemical bonds and valence electrons structure features of TiB2 crystal are studied by self-consistent-field discrete variational Xα method. The relationship between crystalline structure, electrons structure and mechanical, electric properties is discussed. It is shown that the chemical bonds consisting in TiB2 crystal are mixing bond of Ti2+ with B-, σ bond of B- with B- and π bond formed by 2pπ electrons of B-. The conducting band and valence band are mainly formed by the valence electrons locating in Ti3d and B2p orbits. These valence electrons can transmit in TiB2 crystal under electric current through the π bond.
Key words: titanium diboride; valence electron structure; quantum chemistry
