Structural modifications in titania-doped tantalum pentoxide crystals: a Raman scattering study

被引:24
作者
Dobal, PS
Katiyar, RS [1 ]
Jiang, Y
Guo, R
Bhalla, AS
机构
[1] Univ Puerto Rico, Dept Phys, Rio Piedras, PR 00931 USA
[2] Penn State Univ, Mat Res Lab, University Pk, PA 16802 USA
来源
INTERNATIONAL JOURNAL OF INORGANIC MATERIALS | 2001年 / 3卷 / 02期
基金
美国国家航空航天局;
关键词
oxides; crystal growth; Raman spectroscopy; phase transactions;
D O I
10.1016/S1466-6049(01)00003-4
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
Tantalum pentoxide (Ta2O5) is promising for coating and piezoelectric applications and has been considered as the dielectric gate material for the next generation of memory devices. In this work, TiO2-doped Ta2O5 crystals were prepared using the laser-heated pedestal growth technique, as grown specimens were found to crystallize in monoclinic phase at room temperature. The structural modifications in these crystals resulting from variation of TiO2 composition (0-11%) and temperature (-248-900 degreesC) were studied using Raman spectroscopy. The low frequency external modes (upsilon < 100 cm(-1)) that originate from the interaction between TaOn5-2 eta/Ta6O12+6 clusters/polyhedra exhibit a strong compositional and temperature dependence in terms of their intensity and frequency variations. The Raman spectral evolutions suggested a monoclinic to orthorhombic structural phase transition at about 327, 397, 487, and 577 degreesC For 0, 5, 8, and 11% TiO2-doped Ta2O5, respectively. (C) 2001 Elsevier Science Ltd. All lights reserved.
引用
收藏
页码:135 / 142
页数:8
相关论文
共 52 条
[1]   LOW-TEMPERATURE SYNTHESIS, PYROLYSIS AND CRYSTALLIZATION OF TANTALUM OXIDE GELS [J].
BANSAL, NP .
JOURNAL OF MATERIALS SCIENCE, 1994, 29 (19) :5065-5070
[2]  
BHALLA AS, IN PRESS
[3]   VIBRATIONAL-SPECTRA OF 1-2 ORDERED PEROVSKITES [J].
BLASSE, G ;
CORSMIT, AF .
JOURNAL OF SOLID STATE CHEMISTRY, 1974, 10 (01) :39-45
[4]   HIGH-PERFORMANCE TANTALUM OXIDE CAPACITORS FABRICATED BY A NOVEL REOXIDATION SCHEME [J].
BYEON, SG ;
TZENG, YH .
IEEE TRANSACTIONS ON ELECTRON DEVICES, 1990, 37 (04) :972-979
[5]   ENHANCEMENT OF THE DIELECTRIC-CONSTANT OF TA2O5 THROUGH SUBSTITUTION WITH TIO2 [J].
CAVA, RF ;
PECK, WF ;
KRAJEWSKI, JJ .
NATURE, 1995, 377 (6546) :215-217
[6]   Improvement of the dielectric properties of Ta2O5 through substitution with Al2O3 [J].
Cava, RJ ;
Peck, WF ;
Krajewski, JJ ;
Roberts, GL ;
Barber, BP ;
OBryan, HM ;
Gammel, PL .
APPLIED PHYSICS LETTERS, 1997, 70 (11) :1396-1398
[7]   Dielectric properties of Ta2O5-SiO2 polycrystalline ceramics [J].
Cava, RJ ;
Krajewski, JJ ;
Peck, WF ;
Roberts, GL .
JOURNAL OF APPLIED PHYSICS, 1996, 80 (04) :2346-2348
[8]   ION-BEAM SPUTTERING OF (TA2O5)(X)-(SIO2)(1-X) COMPOSITE THIN-FILMS [J].
CEVRO, M .
THIN SOLID FILMS, 1995, 258 (1-2) :91-103
[9]   Tantalum pentoxide (Ta2O5) thin films for advanced dielectric applications [J].
Chaneliere, C ;
Autran, JL ;
Devine, RAB ;
Balland, B .
MATERIALS SCIENCE & ENGINEERING R-REPORTS, 1998, 22 (06) :269-322
[10]   Matrix-isolation infrared spectroscopic studies on ablated products generated from laser ablation of Ta2O5 and Ta in ambient O2/Ar gas [J].
Chen, MH ;
Wang, X ;
Zhang, LN ;
Yu, M ;
Qin, QZ .
CHEMICAL PHYSICS, 1999, 242 (01) :81-90