Bulk and Nanomaterials Synthesis Experiment

bug out and Nanomaterials implication ExperimentIntroductionIn recent years, bulk and nano materials in several areas of pure and applied sciences have captivated a heavy(p) interest amongst the researchers. Because of their fascinating and tremendous properties with great potential in numerous applications such as solid resign lasers, lamp industry, colour displays, etc (Senthil et al, 2001 Tamrakar et al, 2013a Tamrakar et al, 2013b Tamrakar et al, 2014a Tamrakar et al, 2014b) these bulk and nano materials having great interests of research.Experimental Section2.1. Materials and SynthesisSamarium oxide (Sm2O3) and atomic number 62 process (Sm(NO3)3.6H2O) were employ as the rare man bases of K3Gd(PO4)2Sm3+ in the following synthesis methods. Urea (NH2CONH2) and citric acid monohydrate (C6H8O7.H2O) were apply as fuels in electrocution and citrate gel burning methods. The sensible materials in carbonate form were used in solid solid ground method whereas in case of bur ning at the stake and citrate gel method it could be used in nitrate form.2.1.1. Synthesis of undoped K3Gd(PO4)2 and Sm3+ doped K3Gd(PO4)2 by solid state methodThe raw materials potassium carbonate (K2CO3), gadolinium oxide (Gd2O3), ammonium dihydrogen orthophosphate (NH4H2PO4) and samarium oxide (Sm2O3) of spirited purity were mixed and grounded unneurotic with the smallest possible amount of ethanol in an agate mortar for an hour to buzz off a homogeneous mixture. The stoichometric amount of starting materials was weighed gibe to the balanced chemical substance reactions for the undoped K3Gd(PO4)2 (equation (1)) and Sm3+ doped K3Gd(PO4)2 (equation (2)) and are given as followsThe mixed powderise was transferred to the aluminium oxide crucible and placed into the muffle furnace at 850 C for 7 hours. The ready phosphors were cooled to room temperature and grounded to obtain delightful powder.2.1.2. Synthesis of undoped K3Gd(PO4)2 and Sm3+ doped K3Gd(PO4)2 by combustion meth od with urea (NH2CONH2)Urea (NH2CONH2) as a fuel used for the preparation of the undoped K3Gd(PO4)2 and Sm3+ doped K3Gd(PO4)2 by combustion method. The reagents used were potassium nitrate (KNO3), gadolinium oxide (Gd2O3), ammonium dihydrogen orthophosphate (NH4H2 PO4), urea (NH2CONH2) and samarium nitrate (Sm(NO3)3.6H2O) of high purity. The materials were weighed according to the balanced chemical reactions (equations (3 4)) given belowThe stoichometric ratio of reagents was unbroken at unity, so that the heat liberated during combustion be maximized for drop combustion. The weighed reagents were dissolved in a small amount of distilled water and exhaustively mixed in an agate mortar to obtain a paste. The obtained paste was transferred to the aluminum oxide crucible and inserted into the pre-heated muffle furnace sustained at 600. The combustion process occurs with the phylogeny of the large amount of gasses. The whole reaction takes 3-5 minutes to complete. The final snow-c lad foamy product was cooled to room temperature and ground to obtain hunky-dory powder. The fine powder then further annealed at 850 for 3 h to deliver complete crystallanity.2.1.3. Synthesis of undoped K3Gd(PO4)2 and Sm3+ doped K3Gd(PO4)2 by citrate-gel combustion method with citric acid (C6H8O7.H2O)Potassium nitrate (KNO3), gadolinium oxide (Gd2O3), ammonium dihydrogen orthophosphate (NH4H2 PO4), samarium nitrate (Sm (NO3)3.6H2O), citric acid monohydrate (C6H8O7.H2O) of high purity was used as the starting materials for the preparation of the undoped K3Gd(PO4)2 and Sm3+ doped K3Gd(PO4)2. The citrate gel was nimble according to the following chemical reactionsThe reactants in stoichometric amounts were weighed according to equations (5 6) and dissolved together in 10 ml distilled water. The mixed solution was heated to 85C on a hot plate with continuous stirring for 2 hours to obtain a viscous gel. The obtained gel was placed into the pre-heated muffle furnace kept up(p) at 6 00. After several minutes, the gel boiled followed by organic evolution of huge amounts of gases. Eventually, spontaneous ignition occurred and the gel underwent combustion. The whole process finish within a few minutes. The final products were cooled to room temperature and grounded to obtain fine powder. The fine powder, then further annealed at 850 for 3 h to examine that all the unwanted impurities were evaporated and only the higher temperature pure monoclinic descriptor of K3Gd(PO4)2 remains as the final product.2.2. CharacterizationThe X-ray powder diffraction patterns of the synthesizingd powders were save by employ Philips Xpert MPD system with Cu K radiation (1.5406 ) operated at 40 kV and 30 mA. The 2 was change in the range of 10 2 60 with step size of 0.01 (2) and count time of 18s /step. The lattice parameters were calculated using unit electric cell program . The diffuse reflectance spectra were recorded using a Shimadzu UV-VIS-2600 trope beam spectrophotom eter coupled with an ISR (integrating sphere assembly). The photoluminescence (PL) (excitation and emanation spectra) and the lifetime measurements of the synthesized phosphors were recorded using a Cary-Eclipse Spectrofluorometer equipped with a 150W Xenon lamp as an excitation source with slit width 5 nm and 2.5 nm for excitation and emission monochromator. All the measurements were per organize at room temperature.3. Results and discussion3.1. Phase formationThe powder XRD patterns of the Sm3+ doped K3Gd(PO4)2 samples synthesized by solid state, combustion and citrate gel combustion methods were measured. The patterns are shown in figure 1 and compared with that of the JCPDS card 049-1085 (K3Gd(PO4)2). The XRD patternsof Sm3+ doped K3Gd(PO4)2 phosphor indicates a pure phase of the standard K3Gd(PO4)2 and all the peaks were in good obligation which belongs to the monoclinic phase with space group P21/m 20. Also the XRD shows that the formed materials are in crystalline and homo geneous forms.The particle size of the prepared samples have been calculated from the full width half maximum (FWHM) of the knifelike peaks using Debye Scherer formula.Here, D is particle size, k is the Scherrers constant (0.89), is FWHM (full width half maximum), = 1.54 A is the wavelength of X-ray source (Cu (K) radiation), is Bragg angle of the X-ray diffraction peak.The modal(a) particle size of the Sm3+ doped K3Gd(PO4)2 phosphor prepared by solid state method was found approximately 39 nm, while those prepared by combustion and citrate gel methods were found to be 23 nm and 27 nm. The decrease in the particle size is due to append in the FWHM of the XRD peaks for the phosphor synthesized by combustion method and citrate gel combustion method. The variation of particle size with FWHM is also tabulated in table .References