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Low‐Temperature Hydrothermal Synthesis of Ultrafine Strontium Hexaferrite Nanoparticles
Author(s) -
Primc Darinka,
Drofenik Miha,
Makovec Darko
Publication year - 2011
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/ejic.201100326
Subject(s) - ostwald ripening , hydrothermal circulation , nanoparticle , strontium , chemistry , hydrothermal synthesis , chemical engineering , hematite , mineralogy , nanotechnology , nuclear chemistry , materials science , organic chemistry , engineering
Ultrafine strontium hexaferrite (SrFe 12 O 19 ) nanoparticles have been synthesized by the hydrothermal treatment of an appropriate suspension of Sr and Fe hydroxides in the presence of a large excess of OH – at temperatures between 130 and 170 °C. To avoid the parallel formation of any undesired hematite (α‐Fe 2 O 3 ) during the synthesis, a large excess of Sr in the starting composition (Fe/Sr = 3) had to be used. When the treatment was performed below 170 °C, ultrafine nanoparticles were formed. The TEM images show they have a disc‐like shape, approximately 12 nm wide, but only around 4 nm thick. The EDS analysis showed their composition corresponded to SrFe 12 O 19 . When the temperature of the hydrothermal treatment exceeded 170 °C, larger hexagonal platelet crystals appeared as a consequence of Ostwald ripening. The evolution of the size and morphology of the nanoparticles with the temperature of the hydrothermal treatment was also monitored by XRD and measurement of the magnetic properties.