Free Access
Microsc. Microanal. Microstruct.
Volume 6, Number 5-6, October / December 1995
Page(s) 611 - 619
Microsc. Microanal. Microstruct. 6, 611-619 (1995)
DOI: 10.1051/mmm:1995151

Microstructural and Microanalytical Characterization of Pd Clusters in ORMOCER Matrix

Massimo Catalano1, 2, Elvio Carlino1, Maria Antonnella Tagliente1, Antonio Licciulli1 et Leander Tapfer1

1  Centro Nazionale Ricerca e Sviluppo Materiali (PASTIS-C.N.R.S.M.), Strada Statale 7 Appia km. 712, 72100 Brindisi, Italy
2  Istituto per lo studio di nuovi Materiali per l'Elettronica del Consiglio Nazionale delle Ricerche (IME-CND), Università di Lecce, Via Arnesano, 73100 Lecce, Italy

Noble-metal clusters dispersed in glass matrix are of great interest for their technological applications such as heterogeneous catalysis, in the realization of non-linear optical devices, in sensor technology, for absorption control in solar reflecting glasses ( ${\rm IROX}^{\rm TM}$ coatings) etc. The physical properties of these materials strongly depend on cluster concentration, size distribution and on their structural and chemical nature. High spatial resolution structural and analytical characterization techniques are needed to understand the cluster formation mechanism and the physical properties of these materials. In this work, palladium clusters dispersed in ORMOCER matrix via a modified sol-gel process are structurally and chemically characterized by conventional transmission electron microscopy, high-resolution electron microscopy, electron nanodiffraction and X-ray diffractometry, in order to obtain information on the clusters shape, structure, spatial distribution in the matrix and chemical nature. Samples heat treated both in inert $\rm N_2$ atmosphere and in air at 400 °C for different times are analyzed in order to obtain a deeper insight in the formation and structural evolution of the clusters and in the oxidation process. In fact after heat treatment in air, clusters oxidation occurs and a PdO shell surrounding a core with different structure $\sim 1.5$ nm in diameter is formed. Heat treatment in inert $\rm N_2$ atmosphere does not affect the clusters shape, structure and distribution.

6146 - Structure of solid clusters, nanoparticles, and nanostructured materials.
6480G - Microstructure.
8140G - Other heat and thermomechanical treatments.

Key words
crystal microstructure -- electron diffraction -- heat treatment -- metal clusters -- palladium -- particle size -- sol gel processing -- transmission electron microscopy -- X ray diffraction -- microstructural characterization -- microanalytical characterization -- Pd clusters -- ORMOCER matrix -- noble metal clusters -- glass matrix -- spatial distribution -- N sub 2 atmosphere -- structural evolution -- oxidation process -- heat treatment -- oxidation -- cluster concentration -- size distribution -- high spatial resolution structural characterization -- PdO shell -- modified sol gel process -- transmission electron microscopy -- high resolution electron microscopy -- electron nanodiffraction -- X ray diffractometry -- 400 C -- Pd -- N sub 2

© EDP Sciences 1995