Magnetic susceptibility and ¹⁵¹Eu Mössbauer studies on cubic ternary compounds: EuPtSi and EuPdSi

Two new equiatomic ternary compounds, EuPtSi and EuPdSi, have been synthesized and are found to crystallize in the cubic LaIrSi type structure. The magnetic susceptibility of both compounds follows Curie-Weiss behavior in the temperature range 10 to 300 K with an effective magnetic moment close to that of Eu²⁺ moment. The paramagnetic Curie temperatures are 5 K for EuPtSi and 9 K for EuPdSi. There is no clear indication of magnetic ordering in the susceptibility of both the compounds down to 4.2 K. However, ¹⁵¹Eu Mössbauer studies show a hyperfine split pattern in EuPtSi at 4.2 K indicating the onset of magnetic ordering. The ¹⁵¹Eu isomer shifts are temperature independent and are characteristic of the divalent Eu ion. All these results establish that the Eu ions are in a stable divalent state in these compounds.