title: Combustion synthesized tetragonal ZrO2: Eu(3+) nanophosphors: structural and photoluminescence studies.
abstract: Novel crystalline tetragonal ZrO2: Eu(3+) phosphors were prepared by a facile and efficient low temperature solution combustion method at 400±10 °C using oxalyl dihydrazide (ODH) as fuel. The powder X-ray diffraction patterns and Rietveld confinement of as formed ZrO2: Eu(3+) (1-11 mol%) confirmed the presence of body centered tetragonal phase. The crystallite size estimated from Scherrer's and W-H plots was found to be in the range of 7-17 nm. These results were in good agreement with transmission electron microscopy studies. The calculated microstrain in most of the planes indicated the presence of tensile stress along various planes of the particles. The observed space group (P42/nmc) revealed the presence of cations in the 2b positions (0.75, 0.25, 0.25) and the anions in the 4d positions (0.25, 0.25, 0.45). The optical band gap energies estimated from Wood and Tauc's relation was found to be in the range 4.3-4.7 eV. Photoluminescence (PL) emission was recorded under 394 and 464 nm excitation shows an intense emission peak at 605 nm along with other emission peaks at 537, 592, 605 and 713 nm. These emission peaks were attributed to the transition of (5)D0→(7)FJ (J=0, 1, 2, 3) of Eu(3+) ions. The high ratio of Intensity of ((5)D0→(7)F2) and ((5)D0→(7)F1) infers that Eu(3+) occupies sites with a low symmetry and without an inversion center. CIE color coordinates indicated the red regions which could meet the needs of illumination devices.
authors: Department of Physics, Lal Bahadur Shastry Government First Grade College, Bangalore 560 032, India. Electronic address: vidyays.phy@gmail.com.
authors: Y S
authors: YS
authors: Vidya
authors: Research Center, Department of Science, East West Institute of Technology, Bangalore 560 091, India. Electronic address: ananth.che@gmail.com.
authors: K S
authors: KS
authors: Anantharaju
authors: Prof. C.N.R. Rao Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103, India.
authors: H
authors: H
authors: Nagabhushana
authors: Vice Chancellor, Chhattisgarh Swami Vivekananda Technical University, North Park Avenue, Sector-8, Bhilai, Chhattisgarh 490 009, India.
authors: S C
authors: SC
authors: Sharma
authors: Research Center, Department of Science, East West Institute of Technology, Bangalore 560 091, India.
authors: H P
authors: HP
authors: Nagaswarupa
authors: Research Center, Department of Science, East West Institute of Technology, Bangalore 560 091, India.
authors: S C
authors: SC
authors: Prashantha
authors: Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India.
authors: C
authors: C
authors: Shivakumara
authors: Prof. C.N.R. Rao Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103, India.
authors: Danithkumar
mesh_terms: D005063:Europium / Q000737:chemistry*; D049449:Luminescence; D008163:Luminescent Measurements / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D011208:Powders; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D013816:Thermodynamics; D014961:X-Ray Diffraction; D015040:Zirconium / Q000737:chemistry*
chemical_list: D011208:Powders; D005063:Europium; D015040:Zirconium; C028541:zirconium oxide
keywords: Photoluminescence; Rietveld; Solution combustion synthesis; ZrO(2): Eu(3+)