It was shown previously that the synthesis of SrRuO3 in an O environment produced non-stoichiometric SrRu1–xO3 compounds with randomly distributed vacancies on the Ru sites, along with a significant reduction in the ferromagnetic ordering temperature. In order to gain insight into the suppression of ferromagnetism, an investigation of the short-range order, Ru magnetic moment, and Ru valence state was carried out. Local studies utilizing 99,101Ru zero-field, spin-echo nuclear magnetic resonance, along with complementary dc magnetization and X-ray diffraction, revealed that the Ru paramagnetic moment above the ordering temperature decreased only slightly from the Ru4+ low-spin (S = 1) value as vacancies were introduced into the Ru sites. On the other hand, the ordered Ru moment measured by low-temperature hysteresis was strongly suppressed along with the ordering temperature. The results presented here did not support the idea of an increase in the average Ru valence state from 4+ to 5+ by the creation of some amount of local Ru5+.

99,101Ru NMR Study of the Ru-Site Vacancies in SrRu1–xO3 Compounds. Z.H.Han, J.I.Budnick, W.A.Hines, P.W.Klamut, B.Dabrowski, M.Maxwell: Physical Review B, 2005, 71[21], 214432 (5pp)