02057nas a2200301   4500008004100000022001400041245007100055210006900126260009200195300001400287490000600301520105500307653003001362653001401392653001401406653001801420100002201438700001601460700002101476700002301497700001801520700001801538700002301556700001901579700002301598700002901621856010501650       2007                        eng d  a1533-488000aLow temperature synthesis of magnetite and maghemite nanoparticles0 aLow temperature synthesis of magnetite and maghemite nanoparticl  a26650 THE OLD RD, STE 208, VALENCIA, CA 91381-0751 USAbAMER SCIENTIFIC PUBLISHERScDEC  a4294-43020 v73 a<p>We report on the synthesis of iron oxide nanoparticles below 100 degrees C by a simple chemical protocol. The uniqueness of the method lies in the use of Ferrous ammoniurn sulphate (in conjugation with FeCl3) which helps maintain the stability of Fe-2+ state in the reaction sequence thereby controlling the phase formation. Hexamine was added as the stabilizer. The nanoparticles synthesized at three different temperatures viz, 5 degrees, 27 degrees, and 95 degrees C are characterized by several techniques. Generally, when a mixture of Fe3+ and Fe2+ is added to sodium hydroxide, alpha-Fe2O3 (the anti-ferromagnetic phase) is formed after the dehydration process of the hydroxide. In our case however, the phases formed at all the three temperatures were found to be ferro (ferri) magnetic, implying modification of the formation chemistry due to the specifics of our method. The nanoparticles synthesized at the lowest temperature exhibit magnetite phase, while increase in growth temperature to 95 degrees C leads to the maghemite phase.</p>10alow temperature synthesis10amaghemite10amagnetite10aNanoparticles1 aBhagwat, Shrikant1 aSingh, Hema1 aAthawale, Anjali1 aHannoyer, Beatrice1 aJouen, Samuel1 aLefez, Benoit1 aKundaliya, Darshan1 aPasricha, Renu1 aKulkarni, Shailaja1 aOgale, Satishchandra, B.  uhttps://library.ncl.res.in/content/low-temperature-synthesis-magnetite-and-maghemite-nanoparticles-002208nas a2200217   4500008004100000022001400041245012400055210006900179260011000248300001400358490000700372520133700379100001601716700002201732700001801754700001801772700002501790700002301815700002501838856012701863       2010                        eng d  a1463-907600aElucidation of the role of hexamine and other precursors in the formation of magnetite nanorods and their stoichiometry0 aElucidation of the role of hexamine and other precursors in the   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a3246-32530 v123 a<p>Hexamine is known to assist anisotropic growth of metal oxides and the same is also found to be true for magnetite nanosynthesis. In this work we elucidate the role of hexamine and other precursors in the formation of magnetite nanorods by the hydrothermal route and their stoichiometry. Various others hydrolyzing agents such as sodium hydroxide (NaOH), sodium hydroxide + hexamine, ammonia (NH(3)), ammonia + formaldehyde are also studied. The synthesized nanoparticles are characterized with the help of various techniques such as X-ray diffraction (XRD), FT-IR spectroscopy, UV-VIS-NIR spectroscopy, transmission electron microscopy (TEM), Mossbauer spectroscopy and SQUID magnetization measurements. It is found that only when ferric chloride, ferrous ammonium sulfate (FAS) and hexamine are used, well defined nanorods are formed. When sodium hydroxide and hexamine are used as a hydrolyzing system nearly spherical nanoparticles with small size (similar to 13 nm) are formed, as compared to the case of sodium hydroxide alone which leads to bigger cube like nanoparticles. Interestingly the decomposition products of hexamine do not lead to nanorod formation. Thus, slow decomposition of hexamine at elevated temperature and the consequent slow rise in pH is the key to the anisotropic growth of the iron oxide system.</p>1 aSingh, Hema1 aBhagwat, Shrikant1 aJouen, Samuel1 aLefez, Benoit1 aAthawale, Anjali, A.1 aHannoyer, Beatrice1 aOgale, Satishchandra  uhttps://library.ncl.res.in/content/elucidation-role-hexamine-and-other-precursors-formation-magnetite-nanorods-and-their-0