Electron transport in diborides: Observation of superconductivity in ZrB2

  • V. A. Gasparov
  • N. S. Sidorov
  • I. I. Zver’kova
  • M. P. Kulakov
Condensed Matter

DOI: 10.1134/1.1387521

Cite this article as:
Gasparov, V.A., Sidorov, N.S., Zver’kova, I.I. et al. Jetp Lett. (2001) 73: 532. doi:10.1134/1.1387521

Abstract

We report on syntheses and electron transport properties of polycrystalline samples of diborides (AB2) with different transition metals atoms (A=Zr, Nb, Ta). The temperature dependence of resistivity, ρ(T), and ac susceptibility of these samples reveal a superconducting transition of ZrB2 with Tc=5.5 K, while NbB2 and TaB2 have been observed to be nonsuperconducting up to 0.37K. Hc2(T) is linear in temperature below Tc, leading to a rather low Hc2(0)=0.1 T. At T close to Tc, Hc2(T) demonstrates a downward curvature. We conclude that these diborides, as well as MgB2 samples, behave like simple metals in the normal state with usual Bloch-Grüneisen temperature dependence of resistivity and with Debye temperatures 280, 460, and 440 K for ZrB2, NbB2, and MgB2, respectively, rather than T2 and T3, as previously reported for MgB2.

PACS numbers

74.25.Fy74.72.−h

Copyright information

© MAIK "Nauka/Interperiodica" 2001

Authors and Affiliations

  • V. A. Gasparov
    • 1
  • N. S. Sidorov
    • 1
  • I. I. Zver’kova
    • 1
  • M. P. Kulakov
    • 1
  1. 1.Institute of Solid State PhysicsRussian Academy of SciencesChernogolovka, Moscow regionRussia