Mechanism for the metal-conducting behavior of a single crystal

✍ Scribed by Xianyue Han; Zhongyuan Liu; Dongli Yu; Shengwei Xin; Julong He; Bo Xu; Yongjun Tian

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 699 KB
• Volume: 150
• Category: Article
• ISSN: 0038-1098
• DOI: 10.1016/j.ssc.2010.05.013

✦ Synopsis

The temperature-dependent resistivity of a pure CaB 4 single crystal has been observed to demonstrate metal-conducting behavior. The normal Hall-coefficient measurement is indicative of the electrons as the conducting carriers with a room-temperature density of 4.7×10 21 cm -3 . The observed metal-conducting behavior can be understood using a simple model, in which the Ca ions are treated as independent Einstein harmonic oscillators embedded in a Debye rigid boron network. The ab initio calculations of band structure and density of states corroborate the experimentally observed metal-conducting behavior of CaB 4 , showing that it originates mainly from the p orbital of B atom and the hybridized d orbital of Ca atom.