Diluting europium spins - a magnetic and Eu-151 Mossbauer spectroscopic investigation of the solid solution Eu1-xSrxPtIn2

摘要

The indide EuPtIn2 (MgCuAl2 type, Cmcm, a = 448.23(4), b = 1068.64(11), c = 784.09(8) pm, wR(2) = 0.0432, 466 F-2 values, 16 variables) was synthesized by induction-melting of the elements and subsequent annealing. The platinum and indium atoms built up a three-dimensional [PtIn2](2-) polyanionic network (278-282 pm Pt-In) which contains channels that are filled with the europium cations. These bind to the network through shorter Eu-Pt contacts (302-323 pm). Temperature dependent magnetic susceptibility and Eu-151 Mossbauer spectroscopic data manifest divalent europium down to 4.2 K. EuPtIn2 orders ferromagnetically at 32.5 K. EuPtIn2 and SrPtIn2 form a complete solid solution Eu1-xSrxPtIn2 with Vergard type behavior for the lattice parameters. Divalent europium is proven through magnetic data and Mossbauer spectroscopy. The Curie temperature decreases monotonically from 32.5 to 3.1 K in going to Eu0.1Sr0.9PtIn2.