Weak charge-density-wave transition in LaAgSb₂ investigated by transport, thermal, and NMR studies

We report a study of the charge-density-wave (CDW) behavior in LaAgSb ₂ by means of electrical resistivity, Seebeck coefficient, thermal conductivity, specific heat, and nuclear magnetic resonance (NMR) measurements. Except for the Seebeck coefficient, apparent indications of CDW ordering at around 207K were noticed in the physical quantities investigated. On the other hand, all measured physical properties are insensitive to the second CDW formation (∼184K), as the transition character is considerably weaker than the high-temperature one. Further, analyses of the thermal conductivity and NMR Knight shift data revealed that the observed variations are essentially of electronic origin. The present findings are in good agreement with the previous results, indicating that the high-temperature CDW ordering is associated with a small gapping of the Fermi surface with a minor periodic displacement of the crystal lattice in LaAgSb₂.