# Specific heat, magnetic susceptibility, resistivity and thermal expansion of the superconductor ZrB12

@article{Lortz2005SpecificHM,
title={Specific heat, magnetic susceptibility, resistivity and thermal expansion of the superconductor ZrB12},
author={Rolf Lortz and Y. Wang and Satoko Abe and C Meingast and Yu. B. Paderno and Vladimir B. Filippov and Alain F. Junod},
journal={Physical Review B},
year={2005},
volume={72},
pages={024547}
}
• Published 8 February 2005
• Physics
• Physical Review B
In an attempt to clarify conflicting published data, we report new measurements of specific heat, resistivity, magnetic susceptibility, and thermal expansivity up to room temperature for the 6 K superconductor ZrB12, using well-characterized single crystals with a residual resistivity ratio 9. The specific heat gives the bulk result 20/ kBTc=3.7 for the superconducting gap ratio, and excludes multiple gaps and d-wave symmetry for the Cooper pairs. The Sommerfeld constant n=0.34 mJ K 2 gat 1…
57 Citations

## Figures and Tables from this paper

### Electron Structure, Transport, and Superconducting Properties of ZrB 12 , ZrB 2 , YB 6 and MgB 2

We report the review of the measurements of the temperature dependence of the resistivity, ρ(T), magnetic penetration depth, λ(T), the lower, Hc1(T), and upper, Hc2(T), critical magnetic fields, for

### Optical study of electronic structure and electron-phonon coupling in ZrB12

• Physics
• 2007
We report the optical 6 meV–4 eV properties of a boride superconductor ZrB12 Tc=6 K in the normal state from 20 to 300 K measured on high-quality single crystals by a combination of reflectivity and

### Isotope effect in charge transport of LuB12

• Physics
• 2010
The galvanomagnetic properties of single-crystal samples with various isotopic boron compositions have been investigated for the first time for the normal state of superconductor LuB12 (Tc ≈ 0.44 K).

### 10B–11B isotope substitution and superconductivity in ZrB12

• Physics
• 2011
The specific heat of the ZrB12 compound in the normal and superconducting states (TC ≈ 6 K) has been studied in the 1.9–7 K temperature range for high-quality single crystals with different relative

### Phonon density of states, anharmonicity, electron-phonon coupling, and possible multigap superconductivity in the clathrate superconductors Ba 8 Si 46 and Ba 24 Si 100 : Factors behind large difference in T c

• Physics
• 2008
We report a detailed study of specific heat, electrical resistivity, and thermal expansion in combination with inelastic neutron and inelastic x-ray scattering to investigate the origin of

### High Pressure and Superconductivity: Intercalated Graphite Cac 6 as a Model System

• Physics
• 2010
Superconducting CaC6 is found to exhibit two important pressure effects: (i) a large P-induced T c enhancement up to 15.1 K at 7.5 GPa, the highest T c value hitherto reported for graphite

### Recent observation of anomalous superconducting behavior of ultrathin YBCO films and single crystals of cluster borides

We report a number of deviations from conventional behavior in the superconducting properties of ultrathin [1–3unit-cell (UC)] YBa2Cu3O7−x films sandwiched between semiconducting Pr0.6Y0.4Ba2Cu3O7−x

### Electronic and optical properties of ZrB12 and YB6. Discussion on electron‐phonon coupling

• Chemistry
• 2006
We report the optical properties of high-quality single crystals of low temperature superconductors zirconiumdodecaboride ZrB12 (Tc = 5.95 K) and yttrium hexaboride YB6 (Tc = 7.15 K) in the range 6

## References

SHOWING 1-10 OF 26 REFERENCES

### Tunneling and magnetic characteristics of superconducting ZrB 12 single crystals

• Physics
• 2004
Bulk and surface properties of high-quality single crystals of zirconium dodecaboride have been studied in the temperature range from 4.5 K up to the superconducting transition temperature which is

### First-Principles Calculation of the Superconducting Transition in MgB2 within the Anisotropic Eliashberg Formalism

• Physics
• 2002
We present a study of the superconducting transition in MgB2 using the ab initio pseudopotential density-functional method, a fully anisotropic Eliashberg equation, and a conventional estimate for

### Superconductivity at 39 K in magnesium diboride

• Physics
Nature
• 2001
In the light of the tremendous progress that has been made in raising the transition temperature of the copper oxide superconductors (for a review, see ref. 1), it is natural to wonder how high the

### Quasiparticle phenomenology for thermodynamics of strong-coupling superconductors

• Physics
• 1973
We show that reduced critical fields, entropies, and specific heats of superconductors, regardless of “coupling-strength,” can be fitted essentially within experimental errors by curves appropriate

### Andreev-reflection spectroscopy in ZrB12 single crystals

• Physics
• 2004
We present the first results of point-contact spectroscopy (PCS) in single crystals of the boride superconductor ZrB12. The material was first characterized by AC susceptibility and resistivity

### Localized vibrational mode analysis of the resistivity and specific heat of LaB 6

• Materials Science
• 2001
${\mathrm{LaB}}_{6}$ and other hexaborides are inclusion compounds in which the rare earth or other metal ion is weakly bound and sits in an oversized cage'' of boron ions. Here we show that a

### On electron transport in ZrB12, ZrB2, and MgB2 in normal state

• Physics
• 2004
We report on measurements of the temperature dependence of resistivity, ρ(T), for single-crystal samples of ZrB12, ZrB2, and polycrystalline samples of MgB2. It is shown that the cluster compound

### Properties of boson-exchange superconductors

The author reviews some of the important successes achieved by Eliashberg theory in describing the observed superconducting properties of many conventional superconductors. Functional derivative

### Anisotropy and strong-coupling effects on the critical-magnetic-field curve of elemental superconductors

An empirical method of separating strong-coupling effects from anisotropy effects in critical-magnetic-field curves of elemental superconductors is presented. Using Clem's critical-field expressions

### Apparatus for measuring the thermal expansion of solids between 1.5 and 380K

• Materials Science
• 1983
Describes a device for measuring the thermal expansion of solids in the temperature range from 1.5 to 380K, based on a three-terminal capacitor method. The construction of the expansion cell allows a