RT Journal Article T1 The effect of annealing in different atmospheres on the luminescence of polycrystalline TiO_2 A1 Plugaru, R A1 Cremades Rodríguez, Ana Isabel A1 Piqueras de Noriega, Javier AB Polycrystalline samples of titanium oxide were prepared by thermal sintering, in argon and air atmospheres at temperatures ranging from 1100 to 1500 degreesC, from powders of anatase and rutile phases. The samples sintered in argon were further treated in oxygen at the temperature of 800 degreesC for intervals of time up to 8 h. The luminescence emission of the initial powders was situated in the green region, with the peak at 580 nm. The sintering treatment in argon leads to a decrease of the luminescence intensity that appears as a broad band peaked at 550 nm in the case of anatase and as a band peaked at 450 nm in the case of the rutile phase. The sintering treatment in air causes the quenching of the emission in the visible region. In both cases, a sharp and intense emission appears in the infrared region at 800 nm for rutile and 820 nm for the anatase phase. The blue emission is sensitive to the treatment in oxygen atmosphere which causes mainly an intensity increase of the band at 450 nm. The treatment in oxygen results in the reconstruction of the polycrystalline sample surface as hexagonal shape protrusions and large terraces. PB Institute of Physics SN 0953-8984 YR 2004 FD 2004-07-21 LK https://hdl.handle.net/20.500.14352/50851 UL https://hdl.handle.net/20.500.14352/50851 LA eng NO [1] Diebold U 2003 Surf. Sci. Rep. 48 53[2] Asari E and Souda R 2003 Vacuum 68 123[3] Gan S, Liang Y and Baer D R 2000 Surf. Sci. 459 L498[4] Fujino T, Katayama M, Inudzuka K, Okuno T and Oura K 2001 Appl. Phys. Lett. 79 2716[5] Nörembrger H, Tanner R E, Schierbaum K D, Fischer S and Briggs G A D 1998 Surf. Sci. 52–60 396[6] Bennett R A, Poulston S, Stone P and Bowker M 1999 Phys. Rev. B 59 10341[7] Tang H, Prasad K, Sanjines R, Schmid P E and Levy F 1994 J. Appl. Phys. 75 2042[8] Sanjines R, Tang H, Berger H, Gozzo F, Margaritondo G and Levy F 1994 J. Appl. Phys. 75 2945[9] Ghosh A K, Wakim F G and Addiss R R Jr 1969 Phys. Rev. 184 979[10] Deb S K 1972 Solid State Commun. 11 713[11] Tang H, Berger H, Schmidt P E and Levy F 1993 Solid State Commun. 87 847[12] Reynolds D C, Look D C, Jogai B, Van Nostrand J E, Jones R and Jenny J 1998 Solid State Commun. 106 701[13] Rothschild A, Levakov A, Shapira Y, Ashkenasy N and Komem Y 2003 Surf. Sci. 456 532[14] Li M, Hebenstreit W and Diebold U 1998 Surf. Sci. 414 L951[15] Epling W S, Peden C H F, Henderson M A and Diebold U 1998 Surf. Sci. 412/413 333[16] Li M, Hebenstreit W, Gross L, Diebold U, Henderson M A, Jennison D R, Schultz P A and Sears M P 1999 Surf. Sci. 437 173[17] Diebold U, Anderson J F, Ng K O and Vanderbilt D 1996 Phys. Rev. Lett. 77 1322[18] Onishi H and Iwasawa Y 1996 Phys. Lett. 76 791 NO © 2004 IOP Publishing Ltd.International Workshop on Beam Injection Assessment of Microstructures in Semconductors ( 7. 2003. Lille, Francia).This work was supported by MCYT (ProjectMAT2000-2119). RP thanks MCYT for a research grant from the NATO scientific programme. NO MCYT NO NATO scientific programme DS Docta Complutense RD 19 may 2024