TY - JOUR
T1 - Effects of magnetite nanoparticles on optical properties of zinc sulfide in fluorescent-magnetic Fe3O4/ZnS nanocomposites
AU - Roychowdhury, Anirban
AU - Pati, Satya Prakash
AU - Kumar, Sanjay
AU - Das, Dipankar
N1 - Funding Information:
The authors are grateful to Jadavpur University, Kolkata for providing the HRTEM and TG/DTA facilities. The authors thank Dr. A. Saha, UGC DAE CSR, Kolkata for the optical measurements. The magnetization measurements were done at the high magnetic field facility at UGC-DAE CSR, Kolkata created under the DST project No.: IR/S2/PU-0006/2006. A. Roychowdhury acknowledges University Grants Commission, New Delhi for providing Fellowship and also acknowledges UPE program of JU funded by UGC, Govt. of India .
PY - 2014/3
Y1 - 2014/3
N2 - Magnetic-fluorescent Fe3O4/ZnS nanocomposites (NCs) with varying concentration of the constituents have been prepared by a simple chemical route. XRD and TEM measurements confirmed the phase purity and crystallinity of the NCs. Thermal analysis shows that the NCs are stable up to about 500°C. Mössbauer analysis reveals that magnetite in the NCs is nonstoichiometric having cation vacancies at the octahedral sites. UV-vis absorption spectra of the NCs show a shift of the absorption peak towards shorter wavelength indicating modification of the band gap of ZnS after formation of the NCs. Photoluminescence emission (PLE) spectra of the NCs display strong near band edge emission (NBE) in the UV region along with moderately strong emission bands in the visible range caused by electronic transitions involving defect-related energy levels in the band gap of ZnS. FTIR and Raman studies confirm presence of only ZnS and Fe3O4 in the NCs. Dc magnetization measurements show a reduction of magnetization value with increase of ZnS content in the NCs. The irreversibility noticed in the ZFC-FC curves has been attributed to the presence of spin-glass like phase in the NCs caused by relaxing spin moments near the surface of Fe3O4 nanoparticles.
AB - Magnetic-fluorescent Fe3O4/ZnS nanocomposites (NCs) with varying concentration of the constituents have been prepared by a simple chemical route. XRD and TEM measurements confirmed the phase purity and crystallinity of the NCs. Thermal analysis shows that the NCs are stable up to about 500°C. Mössbauer analysis reveals that magnetite in the NCs is nonstoichiometric having cation vacancies at the octahedral sites. UV-vis absorption spectra of the NCs show a shift of the absorption peak towards shorter wavelength indicating modification of the band gap of ZnS after formation of the NCs. Photoluminescence emission (PLE) spectra of the NCs display strong near band edge emission (NBE) in the UV region along with moderately strong emission bands in the visible range caused by electronic transitions involving defect-related energy levels in the band gap of ZnS. FTIR and Raman studies confirm presence of only ZnS and Fe3O4 in the NCs. Dc magnetization measurements show a reduction of magnetization value with increase of ZnS content in the NCs. The irreversibility noticed in the ZFC-FC curves has been attributed to the presence of spin-glass like phase in the NCs caused by relaxing spin moments near the surface of Fe3O4 nanoparticles.
UR - http://www.scopus.com/inward/record.url?scp=84896708845&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84896708845&partnerID=8YFLogxK
U2 - 10.1016/j.powtec.2014.01.076
DO - 10.1016/j.powtec.2014.01.076
M3 - Article
AN - SCOPUS:84896708845
SN - 0032-5910
VL - 254
SP - 583
EP - 590
JO - Powder Technology
JF - Powder Technology
ER -