Y#rium aluminum borated sol-‐gel technology to optical aplication I. Cieślik(1,2), A.Majchrowski(1), K. Kurzydłowski(3), M. Płocińska(3), I. V. Kityk (4) (1)Institute of Applied Physics, Military University of Technology, Kaliskiego 2, 00-908 Warsaw, Poland, icieslik@wat.edu.pl (2) Material Physics Department, National Center for Nuclear Research, A. Sołtana 7, 05-400 Otwock, Poland (3) Faculty of Materials Science and Engineering, University of Technology 02-507 Warsaw, Poland (4)Institute of Physics J. Długosz Częstochowa University 00-908 Częstochowa, Poland
IntroducDon
The purpose of this work was to obtained nanocrystalline sample of yttrium aluminum borate (YAB) doped with rare earth (RE) and transition (TM) metals, development technology deagglomeration and separation of nanoparticles. Ytrrium aluminium borate crystal gave excellent non – linear optical properties and doped have imprtant applications in laser engineering [1]. Conventional technology of YAB by flux method is very difficult. In our method we used sol-gel method to obtained nanopraticles of YAB. Sol-gel method is an efective method for preparing YAB doped chromium, cobalt and manganese. In order to separate nanoparticles of YAB we used concentration gradient method.
Synthesis of y#rium aluminum borate
DeaglomeraDon proces 1) Samples of yttrium aluminum borates, were put into acetic acid to obtained acidic environment. 2) Sodium hydroxide was used to obtain basic range of pH. 3) The pH of studied suspensions ranged from 0.3 to 13.4 pH. 4) The samples were under ultrasonic cleaner (a 32[W]) by 4 or 8 hours for each sample. 5)After that the droplets of solutions were placed on the glass plates. 6) The prepared plates were dried at 120 ˚C for 5 hours to remove water.
a
c
b
1) The first phase of the process based on the polyestrification reaction. Sorbitol and edetic acid were used as polymerizing agents. At this stage brached chains on linear polymers are formed 2) The inorganic precursors were dissoled in water and acid to form the sol medium. Sol was added to the mixture of polymer solution. 3) Thus prepared mixture was left in a crucible for several hours at 90°C in order to concentrate the solution, and the transition from sol gel occurred. 4) After receiving the gel the temperature increased up to 300 °C .
Rys. 1 Yttrium Aluminum Borate doped with Chromium ions – nanocrystal start to grow up 100 oC
Figure 4. Scanning electron microscopy SEM images of YAB: Cr 3+ in different pH preparation a) pH = 0,3 , b) pH = 7 c) pH= 13,4
GeneraDon of second harmony Co Mn Cr
1,0 0,9
SHG [arb.un.]
0,8
Rys. 2 Yttrium Aluminum Borate doped with Chromium ions – nanocrystal grow up 300 oC
5) The resulting sample was subjected to pyrolisis at 1000 °C under cover.
Figure 5 Principal set-up for measurements of the photo- induced optical SGH Fundamental laser indicates 10 ns Nd:YAG laser operating at 1064 nm; M1, M2, M3, M4 – reflecting aluminium mirrors; sh- laser beam shutters; P1, P2- laser beam polarizers; F- green filters, L1, L2 – collimating lenses; PMphotomultiplier
0,7 0,6 0,5 0,4 0,3
0
200
400
600
800
1000
t [s]
Figure 6. Dependence of secon harmonic generation in the YAB Ce 3+,Mn 3+Co
3+ (1% at.).
Rys. 3 Yttrium Aluminum Borate doped chromium ions – after pyrolysis process 1000° C
6) Samples of YAB were cooled and milled in an agate mortar to nanopowder.
nanocrystalline NC aligned under the extremal dc electric field (about 9kV cm -1) versus the time of treatment by the photo inducting 532 nm illumination at 150 K.
Conclusion Ø The sol-gel technology is a simpler and more economical than conventional metods.
References 1)G.Meszaros, E.Svab, E. Beregi, A. Watterich, M. Toth, Physica Bl Magazine, 276-278, 2000 2) I. Cieslik, J. Żmija, A.Majchrowski, P. Morawiak, M. Pępczynska, M. włodarski, „ Synthesis and characteristic of opticla properties of crystalline YAB:Ce, Cr , Journal of Achievements in Materials and Manufacturing Engineering, 2011 3) E. Cavalli, A. Speghini, M. Betinelli, M.O. Ramirez, J.J. Romero, L.E. Bausa , J. Garcia Sole , „ Luminescence of trivalent rare earth ions in the yttrium alluminum borate non linear laser crystal, J. of luminescence, 200
Ø Deaglomeration tehnique allows to obtain destruction completely of aglomerates. Ø The maximal SHG output was obtained at 150 K Ø It was established that the best SHG efficiencies were obtained for the Cr doped YAB samples. It is clear that after 600 s of the samples illumination there was observed some maximum of the SHG. The maximal SHG output was obtained at 150 K
T [°C]
ACKNOWLEDGMENTS: This work was in 2012 year under financial support of the Polish Ministry of Sciences and Higher Education, Key Project POIG.01.03.01−14−016/08 “New photonic materials and their advanced application”.