A laser-deposition approach to compositional-spread discovery of materials on conventional sample sizes

• Published in: Measurement science & technology Vol. 16; no. 1; pp. 21 - 31
• Main Authors: Christen, Hans M, Ohkubo, Isao, Rouleau, Christopher M, Jellison, Gerald E, Puretzky, Alex A, Geohegan, David B, Lowndes, Douglas H
• Format: Journal Article
• Language: English
• Published: United States IOP Publishing 01.01.2005
• Subjects: CARBON; CATALYSTS; DEPOSITION; FORESTS; HEATERS; LASERS; NANOSCIENCE AND NANOTECHNOLOGY; NANOTUBES; OPTIMIZATION; PEROVSKITES; PLATES; SUBSTRATES; SYNCHRONIZATION; SYNTHESIS; THICKNESS
• ISSN: 0957-0233; 1361-6501
• DOI: 10.1088/0957-0233/16/1/004

Parallel (multi-sample) approaches, such as discrete combinatorial synthesis or continuous compositional-spread (CCS), can significantly increase the rate of materials discovery and process optimization. Here we review our generalized CCS method, based on pulsed-laser deposition, in which the synchronization between laser firing and substrate translation (behind a fixed slit aperture) yields the desired variations of composition and thickness. In situ alloying makes this approach applicable to the non-equilibrium synthesis of metastable phases. Deposition on a heater plate with a controlled spatial temperature variation can additionally be used for growth-temperature-dependence studies. Composition and temperature variations are controlled on length scales large enough to yield sample sizes sufficient for conventional characterization techniques (such as temperature-dependent measurements of resistivity or magnetic properties). This technique has been applied to various experimental studies, and we present here the results for the growth of electro-optic materials (Sr(sub x)Ba(sub 1-x)Nb(sub 2)O(sub 6)) and magnetic perovskites (Sr(sub 1-x)Ca(sub x)RuO(sub 3)), and discuss the application to the understanding and optimization of catalysts used in the synthesis of dense forests of carbon nanotubes.