Antiferromagnetic exchange weakening in the TbRhIn5 intermetallic system with Y-substitution

We report measurements of the temperature dependent specific heat and magnetic susceptibility in single crystals of the series of intermetallic compounds Tb1−xYxRhIn5 (nominal concentrations x = 0.0, 0.15, 0.3, 0.4, 0.5, 0.7). A mean field approximation to simulate the macroscopic properties along the series has been used. Neutron diffraction data in powdered samples of Tb0.6Y0.4RhIn5 and Tb0.6La0.4RhIn5 reveal antiferromagnetic (AFM) propagation vector k→=[12012] with the magnetic moments oriented along the tetragonal c axis or canted from this axis, respectively for Y and La-substitutions. Considering both the simulations of the magnetic exchange and neutron diffraction data, we discuss the role of combined effects of crystalline electric field (CEF) perturbations and dilution in the evolution of magnetic properties with Y and La contents. In particular, we found negligible variations of the Bnm parameters along the Y series. The decrease of TN with x is fully dominated by magnetic dilution effects.