Production of high-quality Pt single crystals using a new flame float-zone method

Abstract

Production of large and dislocation-free Pt single-crystal electrodes using a new flame float-zone (FFZ) method, of which the key technique is to use dislocation-free Pt for making a Pt single-crystal bead, is proposed. The qualities of the Pt single crystal using the FFZ method and a flame melting (FM) method, the so-called Clavilier's method, are compared using electrochemical measurements and AFM observations. To obtain wide, atomically flat terraces with monatomic steps at Pt(111) and Pt(100), the necessary annealing time for FFZ Pt single crystal and FM Pt single crystal was 180 min and >180 min, respectively. The epitaxial rearrangement of surface atoms would be performed rapidly for the FFZ Pt single crystal. Moreover, the roughness of the FM Pt(111) and Pt(100) planes after etching was significantly greater than that of the FFZ Pt(111) and Pt(100) planes. Thus the surface structures of the Pt single crystal made using the FFZ method seem to be a more perfect crystal than those using the FM method. The FFZ Pt(100) facets for measurements of STM, AFM and IR are more desirable than the FM Pt(100) facets because the size of FFZ Pt(100) facets is larger than that of the FM(100) facets.