Abstract Single crystalline NdBa 2Cu 3O x (Nd123) superconductors with dispersed Nd 4Ba 2Cu 2O 10 (Nd422) particles were produced by the floating zone partial melting and solidification (FZPMS) method. The initial composition of the precursor material was Nd 1.8Ba 2.4Cu 3.4O x with or without 0.1 wt% Pt addition. FZPMS was carried out in a low oxygen partial pressure atmosphere. Microstructure of quenched samples were investigated by optical microscopy, scanning electron microscopy (SEM) and electron probe microanalysis (EPMA). Furthermore, superconductive properties were measured by superconducting quantum interference device (SQUID). The results of SQUID measurements indicate that the critical temperature ( T c) of the samples with Pt addition so produced with the oxygen heat treatment (623 K for 300 h) was 94 K and the critical current density ( J c) was 2.3×10 4 A/cm 2 at 77 K, 0.2 T.