“…7 is that the maximum value for T C with Gd doping is 125 K. We cannot reproduce the higher values (e.g., 130-170 K) reported in the literature. 7,8,9,10,12,13,14,15,18 It was inferred that stoichiometry problems could add to an extra increase in T C . 5,11 In this respect it is interesting to note that indeed oxygen deficiencies in Gd-free EuO samples already lead to enhancements of T C up to 140-150 K. 17,19,20 In our case we can exclude the presence of oxygen vacancies: the samples all were grown under Eu-distillation conditions, and under these conditions we have observed for the pure EuO films that they have the bulk T C value of 69 K and that they remain semiconducting and are, in fact, extremely insulating down to the lowest temperatures.…”