1. NEW MULTIFUNCTIONAL CERAMICS: ELABORATION, CHARACTERIZATIONS AND APPLICATIONS University of Science and Technology Houari Boumediene (USTHB) Taïbi – Benziada Aldjia – Laldja (http://perso.usthb.dz/~lbenziada) Agence Thématique de Recherche en Sciences et Technologie (ATRST) Avenue Pasteur, ENSA ex INA Belfort, B.P 62 – Hacene Badi, El-Harrach, Alger Tél : 021 52 68 01 / 02 – Fax : 021 52 62 40 – E-mail : Contacts@atrst.dz http://www.atrst.dz INTRODUCTION Materials have always represented an essential aspect of Human Society but, nowadays, the Material became synonymous with Existence for any Industry. For example, in New Technologies of Information and Communication (NTIC), the Progress and Success are closely linked to the development of Advanced Ceramics with higher and higher performances but also with lower and lower factory cost to be competitive on the huge market of microelectronics. INTEREST FOR MATERIALS ABO 3 RELATED MATERIALS Among the new engineering ceramics, ABO 3 perovskites share several properties like piezoelectricity, pyroelectricity and ferroelectricity that make them very attractive for Microelectronic Industry. Moreover, with the devices miniaturization, ATiO 3 (A = Ca, Sr, Ba) ceramics became key materials for the development of smart systems with artificial intelligence. Up to now, the varied PZT have dominated the market of microelectronic components. However, the toxicity of Pb is a serious threat to human health and environment. Therefore, extensive research is actually oriented toward the development of green materials. CERAMIC PRODUCTS Among the various applications of ABO 3 materials we can cite as examples: Capacitors Capacitors Sensors Sensors Resonators Resonators Piezoelectric actuators Piezoelectric actuators Pyroelectric infrared detectors Pyroelectric infrared detectors Electro-optical modulators Electro-optical modulators Computer memories... Computer memories... APPLICATIONS OF PEROVSKITES FRAMs DRAMs HDD T. Shiosaki, The recent progress in the research and development for ferroelectric memory in Japan (1997) CONCLUSIONS Bulk ceramics A 1-x M x Ti 1-x Li x O 3-3x F 3x (A = Ca, Sr or Ba) have been sintered at low temperature thanks to the admixture MF 2 (M= Ca or Pb) and LiF fluorides. Bulk ceramics A 1-x M x Ti 1-x Li x O 3-3x F 3x (A = Ca, Sr or Ba) have been sintered at low temperature thanks to the admixture MF 2 (M= Ca or Pb) and LiF fluorides. The oxifluorides deriving from CaTiO 3 are promising materials to manufacture class I capacitors and resonators for microwave circuits. The oxifluorides deriving from CaTiO 3 are promising materials to manufacture class I capacitors and resonators for microwave circuits. (Sr,M)(Ti,Li)(O,F) 3 ceramics could be used in piezoelectric devices and are potential candidates for the fabrication of type I capacitors. (Sr,M)(Ti,Li)(O,F) 3 ceramics could be used in piezoelectric devices and are potential candidates for the fabrication of type I capacitors. The ceramics related to BaTiO 3 could be of interest for Z5U multilayer capacitors or as filters for electromagnetic waves in various devices. The ceramics related to BaTiO 3 could be of interest for Z5U multilayer capacitors or as filters for electromagnetic waves in various devices. Moreover, all these fluorinated materials could be used as photocatalysts in H 2 O decomposition to get clean energy. Moreover, all these fluorinated materials could be used as photocatalysts in H 2 O decomposition to get clean energy. SAMPLES PREPARATION ACO 3 +TiO 2 Grinding, Calcination ATiO 3 + CO 2 Grinding, Pressing (10 8 Pa) Sintering (900 °C or 1000 °C, 1 or 2 h) x MF 2 + x LiF A 1-x M x (Ti 1-x Li x )O 3-3x F 3x MICROSTRUCTURES CaTi 0.95 Li 0.05 O 2.85 F 0.15  = 21.9 % Ba 0.95 Ca 0.05 Ti 0.95 Li 0.05 O 2.85 F 0.15  = 13.5 % Sr 0.95 Ca 0.05 Ti 0.95 Li 0.05 O 2.85 F 0.15  = 18.7 % Ba 0.97 Pb 003 Ti 0.97 Li 0.03 O 2.91 F 0.09  = 16.9 % DIELECTRIC PROPERTIES ε' r T (K) 10 2 Hz 5x10 2 Hz 10 3 Hz 5x10 3 Hz 10 4 Hz 5x10 4 Hz 10 5 Hz 2x10 5 Hz ε" r T (K) 10 2 Hz 5x10 2 Hz 10 3 Hz 5x10 3 Hz 10 4 Hz 5x10 4 Hz 10 5 Hz 2x10 5 Hz CaTi 0.95 Li 0.05 O 2.85 F 0.15 ceramic CaTi 0.95 Li 0.05 O 2.85 F 0.15 ceramic 10 2 Hz 5x10 2 Hz 10 3 Hz 5x10 3 Hz 10 4 Hz 5x10 4 Hz 10 5 Hz 2x10 5 Hz 10 2 Hz 5x10 2 Hz 10 3 Hz 5x10 3 Hz 10 4 Hz 5x10 4 Hz 10 5 Hz 2x10 5 Hz Sr 0.95 Ca 0.05 Ti 0.95 Li 0.05 O 2.85 F 0.15 ceramic Sr 0.95 Ca 0.05 Ti 0.95 Li 0.05 O 2.85 F 0.15 ceramic ε" r ε' r Ba 0.97 Pb 0.03 Ti 0.97 Li 0.03 O 2.91 F 0.09 ceramic Ba 0.97 Pb 0.03 Ti 0.97 Li 0.03 O 2.91 F 0.09 ceramic log 10 f (Hz) ε" r ε' r 3000 2000 1000 4000 5 6 7 8 0 Ba 0.95 Ca 0.05 Ti 0.95 Li 0.05 O 2.85 F 0.15 ceramic Ba 0.95 Ca 0.05 Ti 0.95 Li 0.05 O 2.85 F 0.15 ceramic