Structural and electronic properties of RPd2 Al2-xGax (RÂ =Â Ce and La) compounds

The compounds from CePd2Al2-xGax series were studied by means of magnetization and electrical resistivity measurements. The electrical resistivity was measured also on LaPd2Al2-xGax counterparts. The development of structural phase transition with Ga content was investigated and its connection with presence of vibron states was discussed. The structural parameters of CePd2Ga2 were determine for both tetragonal and triclinic structure from powder neutron diffraction data. All studied compounds order antiferromagnetically, the Néel temperature slightly decreases with increasing Ga content. Simultaneously, ferromagnetic correlations are observed in the series and become stronger with Ga concentration. The powder neutron diffraction on CePd2Ga2 proved the antiferromagnetic ground state, which is suppressed by magnetic field of 5 T. We found several possible propagation vectors describing observed magnetic reflection.