Hall effect and electrical conductivity of transition-metal diborides

Correlations among superconductivity, structural instability, and band filling inNb1−xB2at the critical pointXiao1, Li2, Yang3 et al. 2006Phys. Rev. B8150View full textAdd to dashboardCite

“…The superconducting transitions in the MgB 2 materials synthesized under a variety of conditions appear at around the limit of T c as was suggested theoretically several decades ago for BCS [3,5,7]. Actually, superconductivity in the metal borides with an AlB 2 -type structure has been studied for several decades [8,9]. In 1970, Cooper et al reported the presence of superconductivity in both the Nb-B and Mo-B systems, and they also noted that the stoichiometric compounds, NbB 2 and MoB 2 , in general were non-superconductors, and a few B-rich samples such as NbB 2.5 show sharp superconducting transitions [10].…”

“…In 1970, Cooper et al reported the presence of superconductivity in both the Nb-B and Mo-B systems, and they also noted that the stoichiometric compounds, NbB 2 and MoB 2 , in general were non-superconductors, and a few B-rich samples such as NbB 2.5 show sharp superconducting transitions [10]. Recent investigations [7][8][9][10] were mounted into a sintered BN tube. The samples were heated to 1200°C in 10 min and sintered for 0.5 hour under a pressure of 6GPa using a cubic-anvil-type equipment.…”

Hole superconductivity in MgB2: a high Tc cuprate without Cu

“…The Hall coefficient for other metal diborides with the same crystal structure (Y B 2 , T iB 2 , V B 2 , ZrB 2 , N bB 2 , etc.) has been measured and found to be negative [6,7]. Correspondingly we expect no superconductivity in those compounds (no superconductivity in those compounds has ever been detected to our knowledge).…”

Electronic Structure and Properties of Layered Structures

“…Measurements of the specific heat at low temperatures were performed for several transition metal diborides by Tyan et al [43] and by Castaing et al [44]. Juretschke and Steinitz [33] measured the Hall coefficients and resistivity for a series of transition metal diborides; resistivity measurements were also performed by Dempsey [45]. Silver and Bray [46] studied the nuclear magnetic resonance on TiB 2.…”

“…Among these systems, the transition metal diborides have properties such as high melting temperature, hardness and chemical stability which make them important for technological applications at high temperatures [31]. All the members of this family are metallic [32,33].…”