Deposition of platinum particles at lanthanum manganite cathode (LSM)/scandia-stabilized zirconia (ScSZ)/air three-phase boundaries (TPBs) was investigated. Button-type half-cells consisting of a strontium-doped LSM and a ScSZ electrolyte were operated at T = 1073 K using platinum (Pt) or gold (Au) components as current collectors and lead wires. When Pt components were used, Pt particles were observed only in the vicinity of three-phase boundaries of the cathode after a power generation test. No particle was observed around TPBs of the cathode when Au components were used. (C) 2009 The Electrochemical Society. [DOI: 10.1149/1.3058997] All rights reserved.