Experimental study of electron-phonon properties in ZrB ₂

High quality samples and absence of superconductivity down to 40 mK make of ZrB₂ the best normal state reference system for the superconducting isostructural MgB₂. Actually, the question of pairing has to be focused on the electron-phonon interaction in the normal state. After presenting the resistivity measurements of ZrB₂, we explain the details of the Bloch-Grüneisen and Einstein models used to deduce the first results. We then compare experimental de Haas-van Alphen effect data with theoretical Fermi surfaces to present additional results on electron quasi-particle renormalization. The estimations reveal an isotropic and negligible coupling constant of in average 〈λ_tr〉 = 0.145. The contribution of the coupling to the optical phonon modes is 0.082, in contrast to the known larger coupling of 0.283[3] to the E_2g phonon mode in MgB₂.