Local disorder and structure relation induced by magnetic exchange interactions in A2(Mo1−yMny)2O7 pyrochlores

We present an extended X-ray absorption fine structure study at the Mo K-edge of A2(Mo1−yMny)2O7 (A = Gd, Ho; y 0.05 and 0.10) pyrochlores, as a function temperature composition, coupled to diffractometric magnetic characterizations. Extending reported in our previous paper on pristine A2Mo2O7 compounds these Mo/Mn partially substituted samples, where we hypothesize competition between double-exchange superexchange couplings, aim check which parameters are related nature nearest-neighbor interactions, looking for presence evolution order anomalies. Two Ho samples Ho2(Mo1−yMny)2O7 (y keep spin-glass parent compositions with strong distortion MoO(1)6 octahedron Mo‒Ho Mo‒Mo second shell. On other hand, two Gd2(Mo1−yMny)2O7 ferromagnetic low undoped case, show appearance local scale transition mirrored by quite high disorder coherent lattice frustration after Mn-doping. Therefore, Gd Mn-doped display similar frustrated behavior, differently from corresponding ones.