We have studied the intermetallic compounds EuPd and EuRh2, and the corresponding saturated hydrides, via Eu Mouml;ssbauer spectroscopy, magnetic measurements, and xhyphen;ray diffraction. In both intermetallics, the Mouml;ssbauer parameters, indicative of the environment about the Eu ion, change substantially in the hydriding process and approach those of EuH2. We interpret those changes as evidence that the hydrogen absorption occurs via the formation of EuH2rsquo;rsquo;complexesrsquo;rsquo;. For the EuRh2, a simple thermodynamic argument supports this approach. The EuRh2maintains the same crystal structure under H2absorption, but the Eu3+becomes Eu2+, and the lattice volume increases by 40percnt;. EuPd changes structure under H2absorption, but the Eu remains divalent. Results of magnetic and crystallographic measurements are presented. With partial hydriding, only the pure intermetallic and saturated hydride phases are observed to occur.
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