Density functional theory studies of Nb-benzene and Nb-borazine sandwich clusters and molecular wires

• Published in: Journal of physics. B, Atomic, molecular, and optical physics Vol. 45; no. 2; pp. 025102 - 1-8
• Main Authors: Yang, Zhi, Liu, Xuguang, Liu, Shaoding, Yang, Yongzhen, Li, Xiuyan, Xiong, Shijie, Xu, Bingshe
• Format: Journal Article
• Language: English
• Published: Bristol IOP Publishing 28.01.2012; Institute of Physics
• Subjects: Atomic and molecular physics; Calculations and mathematical techniques in atomic and molecular physics (excluding electron correlation calculations); Clusters; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Density functional theory; Electronic structure of atoms, molecules and their ions: theory; Electronics; Exact sciences and technology; Ferromagnetic, antiferromagnetic, and ferrimagnetic resonances; spin-wave resonance; Ferromagnetism; Magnetic properties; Magnetic resonances and relaxations in condensed matter, mössbauer effect; Mathematical analysis; molecular wires; Physics; Semiconductors; Wire; Semiconductor materials; Ground states; Antiferromagnetic materials; Organic ligand; Theoretical study; Hydrocarbons; Ferromagnetic-antiferromagnetic transitions; Electronic structure; Benzene; Density functional method; Niobium Complexes; Organic compounds; Magnetic properties
• ISSN: 0953-4075; 1361-6455
• DOI: 10.1088/0953-4075/45/2/025102

We systematically explored the stabilities, bonding characteristics, electronic and magnetic properties of sandwich-structured Nbn(benzene)n + 1 and Nbn(borazine)n + 1 clusters (n = 1−4) and molecular wires (n = ∞) based on density functional theory. The calculated results show that the lowest energy Nb2(benzene)3 and Nb3(benzene)4 clusters are antiferromagnets (AFMs), while Nb4(benzene)5 is a ferromagnet (FM). An AFM-to-FM transition occurs at n = 4 in the finite Nbn(benzene)n + 1 system. For Nbn(borazine)n + 1, all the clusters investigated here are ferromagnetically stable. Furthermore, the ground states of infinite [Nb(benzene)]∞ and [Nb(borazine)]∞ molecular wires exhibit different electronic structures. The former is a direct-gap ferromagnetic semiconductor, while the latter is a ferromagnetic half-metal. High stabilities and excellent electronic and magnetic properties of [Nb(benzene)]∞ and [Nb(borazine)]∞ may be exploited for applications in future electronics and spintronics.