Kumar, Rajesh Gautam, S. Hwang, In-Chul Lee, Jae Rhung Chae, K. H. Thakur, Nagesh 2024-01-20T21:31:11Z 2024-01-20T21:31:11Z 2021-09-03 2009-05-15 0167-577X https://pubs.kist.re.kr/handle/201004/132484 Polyhedral nanocrystals of alpha-Fe2O3 are successfully synthesized by annealing FeCl3 on silicon substrate at 1000 degrees C in the presence of H-2 gas diluted with argon (Ar). Uniformly shaped polyhedral nanoparticles (diameter -50-100 nm) are observed at 1000 degrees C and gases flow rate such as; Ar=200 ml/min and H-2 = 150 ml/min. Non-uniform shaped nanoparticles (diameter similar to 20-70 nm) are alsoobserved at an annealing temperature of 950 degrees C with lower gases flow rate (Ar = 100 ml/min and H2 = 75 ml/min). Nanoparticles are characterized in detail by field-emission electron microscopy (FE-SEM). energy dispersive X-ray (EDX) and high resolution transmission electron microscopy (HRTEM) techniques. HRTEM study shows well resolved (110) fringes corresponding to alpha-Fe2O3, and selected area diffraction pattern (SADP) confirms the crystalline nature of alpha-Fe2O3 polyhedral nanoparticles. It is observed that polyhedral formation of alpha-Fe2O3 nanocrystals depends upon annealing temperature and the surface morphology highly rely on the gas flow rate inside the reaction chamber. (C) 2009 Elsevier B.V. All rights reserved. English ELSEVIER SCIENCE BV MAGNETIC-PROPERTIES COPT3 NANOCRYSTALS SIZE CONTROL PARTICLES UNIFORM MORPHOLOGY NANOWIRES NANORODS GROWTH ARRAYS Preparation and characterization of alpha-Fe2O3 polyhedral nanocrystals via annealing technique Article 10.1016/j.matlet.2009.02.003 1 MATERIALS LETTERS, v.63, no.12, pp.1047 - 1050 MATERIALS LETTERS 63 12 1047 1050 scie scopus 000265152700027 2-s2.0-62249161402 Materials Science, Multidisciplinary Physics, Applied Materials Science Physics Article MAGNETIC-PROPERTIES COPT3 NANOCRYSTALS SIZE CONTROL PARTICLES UNIFORM MORPHOLOGY NANOWIRES NANORODS GROWTH ARRAYS Nanomaterials Crystal structure Annealing temperature Polyhedral Gas flow