摘要
The present work concerns sustainable development of environmentally compatible electronic materials. Our investigations have mainly focused on nonlinear orthophosphate compounds and more particularly on eulytite phases. Phosphate eulytites crystallize with the non centrosymmetric space group 1-43d which is compatible piezoelectronic and nonlinear optical properties. Indeed, second harmonic generation （SHG） tests performed on systems of the type BIIaMm（PO4）3 （with Bn= Cd, St, Ba, Pb; MIII= Ln, Bi） showed better performance than KDP （about 100 KH2PO4）1）＇2）. The practical interest of eulytite compounds has been evidenced by various authors in various domain of modem technology; i） medicine （positron tomography）, ii） nuclear industry （fuel rods control）, iii） high energy physics （CERN detector）, iv） etc. Indeed CERN in Geneva is currently using 1300 liters of Bi4（GeO4）3 single crystals. Then, bismuth silicates and bismuth germinate Bi4（SiO4）3 and Bi4（GeO4）3 have important applications in high energy physics as for example, scintillators （ionizing radiation detectors, etc.）. The main aim of our research work is to try to correlate between the chemical composition, the crystalline structure and the physical properties （optical, piezoelectric, etc.） of the phosphate eulytites free of toxic elements with various dopants （Ce3＋, Eu3＋, etc.）. As single crystals are of high cost and difficult to grow, glasses have low technological efficiency of our planed optical applications. Therefore, we are trying to prepare transparent ceramics which are expected to give rather excellent satisfaction. We prepared BaaBi（PO4）3 eulytite phases by two difference methods. One is based on the use of CO2 gas blowing in order to dissolve starting materials （like Baa（PO4）2） and crystallize pure eulytites. The second process is using the sol-gel method.
