  Electromagnetic properties of doped perovskites depend sensitively on the
doping level. Both the superconducting transition temperature of
Bi2Sr2Ca(Pr)Cu2O8+d compounds and the magnetic and electronic transport
properties of La(Sr)Co(Fe)O3 perovskites change dramatically with the doping
level. Apart from doping, oxygen deficiency is influenced by the details of
preparation processes such as calcination and sintering. Simultaneous
determination of constituents is of crucial importance from sample
characterization point of view. Quantitative analysis of perovskite oxides can
be performed by Secondary Neutral Mass Spectrometry (SNMS) which is a suitable
technique to measure the chemical composition of almost any sample because the
flux of atoms sputtered from the sample is representative of the stoichiometry
of the top-most layers. The composition and oxygen content of
Bi2Sr2Ca0.86Pr0.14Cu2O8.4 and La1-xSrxCo0.975Fe0.025O3-d, where 0<x<0.5, were
determined by SNMS. The results show that the method is equally applicable for
insulating and conducting compounds. The observed electromagnetic properties
reflect well the compositions obtained experimentally.
