Speaker
Mr
Witoon Tangwatanakul
(Molecular Technology Research Unit, School of Science, Walailak University, Nakhon Si Thammarat, THAILAND 80161)
Description
Synchrotron X-ray absorption spectroscopy (XAS) was used to complement X-ray
diffraction (XRD) in the characterization of iron oxide nanoparticles synthesized by the
ultrasonic-assisted co-precipitation. The influence of ultrasound was highlighted by XRD
showing impurity phases in the control synthesized without sonication. The hematite ($\alpha$-Fe${}_2$O${}_3$) phase was ruled out by XRD and the XAS spectra revealed the preference of the maghemite ($\gamma$-Fe${}_2$O${}_3$) phase over magnetite (Fe${}_3$O${}_4$). Results from XAS agreed with XRD patterns that $\gamma$-Fe${}_2$O${}_3$ nanoparticles had larger crystallite sizes and lower structural distortions when higher concentrations of Fe(NO${}_3$)${}_3$•9H${}_2$O, FeCl${}_2$•4H${}_2$O and NaOH and a longer sonication/reaction time were used. Moreover, the synthesis with lowly concentrated reagents gives rise to amorphous $\gamma$-Fe${}_2$O${}_3$.
Author
Mr
Witoon Tangwatanakul
(Molecular Technology Research Unit, School of Science, Walailak University, Nakhon Si Thammarat, THAILAND 80161)
Co-authors
Dr
Chitnarong Sirisathitkul
(Molecular Technology Research Unit, School of Science, Walailak University, Nakhon Si Thammarat, THAILAND 80161)
Dr
Rattikorn Yimnirun
(School of Physics, Institute of Science, Suranaree University of Technology and NANOTEC-SUT Center of Excellence on Advanced Functional Nanomaterials, Nakhon Ratchasima, THAILAND 30000)
Dr
Wanwisa Limphirat
(Synchrotron Light Research Institute, Nakhon Ratchasima, THAILAND 30000)
