Undoped, Nb-doped, and (Nb,Cu)-doped SrTiO₃specimens were made using oxide-mix process. Nb-doped specimens having Sr/(Ti+Nb)=0.986 showed grain size decrease as Nb concentration changed from 0.4 to 0.8 mol%. Dark blue color and low electrical resi...
Undoped, Nb-doped, and (Nb,Cu)-doped SrTiO₃specimens were made using oxide-mix process. Nb-doped specimens having Sr/(Ti+Nb)=0.986 showed grain size decrease as Nb concentration changed from 0.4 to 0.8 mol%. Dark blue color and low electrical resistivity were observed in all Nb-doped specimens. When 0.8 mol% Cu was added to 0.4 mol% Nb₂O?-doped composition, grain size decreased to 2 ㎛. However, grain growth inhibition was not found for specimens with 1.6 and 2.4 mol% Cu. Cu seemed to be distributed throughout the grains rather than segregated at grain boundaries and to be present as Cu⁴ion which compensated donor effect of Nb ions.