Temperature dependencies of elastic constants and ultrasonic attenuation of a polycrystalline MgB2 showing high-Tc superconductivity are reported. An electromagnetic acoustic resonance method detected the specimen's resonance frequencies, from which we derived the elastic constants for nonporous MgB2 using micromechanics calculation. The bulk and shear moduli extrapolated to 0 K are determined to be 96.6 GPa and 74.2 GPa, respectively, which gives the Debye temperature ΘD=819 K and the coupling constant λ≈0.76-0.89 with McMillan formula. In the temperature behavior of ultrasonic attenuation, two anomalous peaks are observed near 30 K.
|ジャーナル||Physical Review B - Condensed Matter and Materials Physics|
|出版ステータス||Published - 2002 8 1|
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