Abstract

We report measurements of the de Haas-van Alphen effect on a series of compounds, LaMIn5. The results show that each of the Co and Ir Fermi surfaces exhibits some portions that are two dimensional and some portions that are three dimensional. The most two-dimensional character is exhibited in LaCoIn5, less two-dimensional behavior is seen in LaIrIn5, and no part of Fermi surface of LaRhIn5 is found to have a two-dimensional character. Thus the two dimensionality of portions of the FSs is largely determined by the d character of the energy bands while all of the effective masses remain ≤1.2. This fact has implications for the causes of the heavy fermion nature of superconductivity and magnetism in the Ce-based compounds having similar composition and structure. © 2009 The American Physical Society.