Ta1−xHfxB: a new FeB-prototype superconductor

In this work, we report superconductivity in the new ternary Ta1−xHfxB system. We also show clearly evidence that appropriate amounts of Hf substitution at the Ta site induce the stabilization of the orthorhombic FeB prototype structure in this system. Bulk superconductivity is confirmed by magnetization, electronic transport and specific heat measurements. The Hall signal has temperature dependence and the specific heat data at low temperature deviate from the conventional exponential temperature dependence in Ta0.7Hf0.3B. These results suggest multiband superconductivity in this compound.

[1]  J. E. Gordon,et al.  Specific heat of Mg(B1−xCx)2, x = 0.05, 0.1 , 2013 .

[2]  G. Hilmas,et al.  Oxidation of ultra-high temperature transition metal diboride ceramics , 2012 .

[3]  Karen Willcox,et al.  Kinetics and kinematics for translational motions in microgravity during parabolic flight. , 2009, Aviation, space, and environmental medicine.

[4]  X. Xi,et al.  Two-band superconductor magnesium diboride , 2008 .

[5]  Zi-kui Liu,et al.  Fully band-resolved scattering rate in MgB2 revealed by the nonlinear hall effect and magnetoresistance measurements. , 2008, Physical review letters.

[6]  S. Kasahara,et al.  Superconductivity in the ternary intermetallics of La3Ni4X4 (X = Si and Ge) , 2008 .

[7]  P. Rogl,et al.  Evaluation of the invariant reactions in the Ta-rich region of the Ta-B system , 2006 .

[8]  C. Y. Shigue,et al.  Observation of asymmetric transverse voltage in granular high-Tc superconductors , 2005 .

[9]  H. Takeya,et al.  Magnetic-field dependence of superconducting energy gaps in Y Ni 2 B 2 C : Evidence of multiband superconductivity , 2004, cond-mat/0412486.

[10]  S. Vieira,et al.  Pressure dependence of the upper critical field of Mg B 2 and of Y Ni 2 B 2 C , 2004, cond-mat/0412042.

[11]  H. Harima,et al.  Definitive experimental evidence for two-band superconductivity in MgB2. , 2003, Physical review letters.

[12]  T. Masui,et al.  Normal state transport properties of MgB2 , 2003 .

[13]  V. A. Stepanov,et al.  Direct evidence for two-band superconductivity in MgB2 single crystals from directional point-contact spectroscopy in magnetic fields. , 2002, Physical review letters.

[14]  Japan.,et al.  Review of the superconducting properties of MgB2 , 2001, cond-mat/0108265.

[15]  Yuxing Wang,et al.  Specific heat in the superconducting and normal state (2–300 K, 0–16 T), and magnetic susceptibility of the 38 K superconductor MgB2: evidence for a multicomponent gap , 2001, cond-mat/0103181.

[16]  K. Winzer,et al.  UPPER CRITICAL FIELD PECULIARITIES OF SUPERCONDUCTING YNI2B2C AND LUNI2B2C , 1997, cond-mat/9712174.

[17]  G. Nolze,et al.  POWDER CELL– a program for the representation and manipulation of crystal structures and calculation of the resulting X‐ray powder patterns , 1996 .

[18]  H. Okamoto.  Comment on B-Ta (boron-tantalum) , 1993 .

[19]  E. Helfand,et al.  Temperature and Purity Dependence of the Superconducting Critical Field, H c 2 . III. Electron Spin and Spin-Orbit Effects , 1966 .

[20]  V. Baron,et al.  Production of Superconducting Materials , 1973 .

[21]  R. Kießling,et al.  The Borides of Tantalum. , 1949 .