ULTRA-SMOOTH, HIGHLY ORDERED, THIN-FILMS OF LA0.67CA0.33MNO3+ -D/

We report the growth and characterization of ultra-smooth, highly orde red, strained La2/3Ca1/3MnO3+/-d thin films (approximately 600 Angstro m in thickness). The thin films were deposited by ozone-assisted, bloc k-by-block, molecular beam epitaxy on SrTiO3 (001) substrates without any post-deposition annealing. Scanning tunneling microscopy images sh owed oriented, unit-cell-high terraces characteristic of a step-flow g rowth mechanism. The root-mean-square roughness of the surface of an i maged film was determined to be 2 Angstrom. This same film showed nega tive magnetoresistance values, [R (H = 0) - R (H-applied)]/R (H = 0), at 150 K of 93% and 5% in applied magnetic fields of 5.12 and 4 x 10(- 2) T, respectively. (C) 1996 American Institute of Physics.