(19)

(11)

EP 0 470 130 A1

(12)

(43) Date of publication: 12.02.1992 Bulletin 1992/07 (21) Application number: 90906735.0 (22) Date of filing: 24.04.1990

(51) International Patent Classification (IPC):  C30B 19/ 02( . ) C30B 19/ 06( . ) C30B 19/ 04( . ) (86) International application number: PCT/AU1990/000163 (87) International publication number: WO 1990/012905 (01.11.1990 Gazette 1990/25)

(84) Designated Contracting States: DE FR GB (30) Priority: 26.04.1989 AU 19890003909 (71) Applicant: AUSTRALIAN NUCLEAR SCIENCE AND TECHNOLOGY ORGANISATION Menai, NSW 2234 (AU)	(72) Inventors: ALEXIEV, Dimitri Paddington, NSW 2021 (AU) TAVENDALE, Alister, James ceased (AU) (74) Representative: Seaborn, George Stephen, et al  c/o Edward Evans & Co. Chancery House 53-64 Chancery Lane London WC2A 1SD London WC2A 1SD (GB)