THE ELECTRONIC-STRUCTURE OF STOICHIOMETRIC AND REDUCED CEO2 SURFACES - AN XPS, UPS AND HREELS STUDY

被引:623
作者
PFAU, A [1 ]
SCHIERBAUM, KD [1 ]
机构
[1] UNIV TUBINGEN,INST PHYS & THEORET CHEM,D-72076 TUBINGEN,GERMANY
关键词
D O I
10.1016/0039-6028(94)90027-2
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
The influence of Ce3+-related defects on the electronic structure of stoichiometric CeO2 surfaces is studied by means of detection angle-dependent XPS, UPS and HREELS. Argon sputtering and hydrogen exposure at elevated temperatures lead to high concentrations of Ce3+ at surface and subsurface sites. The latter are identified by the binding energies of the Ce3d core levels, additional emissions of C4f(1)-derived electronic states in the band gap, and characteristic changes in the electronic transitions from occupied into empty electronic states in the valence band region. WS is found to show in particular a high sensitivity for intrinsic surface point defects, even if small concentrations are adjusted in the order of XPS and HREELS detection limits by high-temperature treatment of the CeO, surfaces under UHV conditions or by hydrogen exposure at medium temperatures.
引用
收藏
页码:71 / 80
页数:10
相关论文
共 21 条
[1]  
ANANEV AV, 1993, FIZ KHIM STEKLA, V19, P134
[2]  
CUNNINGHAM JL, COMMUNICATION
[3]  
Duffy JA., 1990, BONDING ENERGY LEVEL
[4]  
GRIMES RW, COMMUNICATION
[5]   THE ELECTRONIC-STRUCTURE OF CEO2 AND PRO2 [J].
KOELLING, DD ;
BORING, AM ;
WOOD, JH .
SOLID STATE COMMUNICATIONS, 1983, 47 (04) :227-232
[6]   COVALENT INSULATOR CEO2 - OPTICAL REFLECTIVITY MEASUREMENTS [J].
MARABELLI, F ;
WACHTER, P .
PHYSICAL REVIEW B, 1987, 36 (02) :1238-1243
[7]   SMALL-POLARON MOBILITY IN NONSTOICHIOMETRIC CERIUM DIOXIDE [J].
NAIK, IK ;
TIEN, TY .
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS, 1978, 39 (03) :311-315
[8]   A THERMODYNAMIC AND ELECTRICAL-CONDUCTIVITY STUDY OF NONSTOICHIOMETRIC CERIUM DIOXIDE [J].
PANHANS, MA ;
BLUMENTHAL, RN .
SOLID STATE IONICS, 1993, 60 (04) :279-298
[9]  
PAUL TW, 1955, J OPT SOC AM, V45, P773
[10]   VALENCE BAND OF GAMMA-CERIUM STUDIED BY ULTRAVIOLET AND X-RAY PHOTOEMISSION SPECTROSCOPY [J].
PLATAU, A ;
KARLSSON, SE .
PHYSICAL REVIEW B, 1978, 18 (08) :3820-3826