Optical emission spectroscopic studies were carried out on the plasma produced by ablation of zinc
oxide target using the third harmonic 355 nm of Q-switched Nd:YAG laser, in vacuum and at three
different ambient gas oxygen pressures. The spatial variations of electron density Ne and electron
temperature Te were studied up to a distance of 20 mm from the target surface. The kinematics of
the emitted particles and the expansion of the plume edge are discussed. The optimum conditions
favorable for the formation of high quality zinc oxide thin films are thereby suggested.
Joseph, Babitha; Dr Prathapachantra Kurup, M R(Cochin University of Science And Technology, November 20, 2014)
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Abstract:
The ability of aroylhydrazones to bind with transition metals is a
developing area of research interest and the coordinating properties of
hydrazones can be tuned by the appropriate choice of parent aldehyde or
ketone and the hydrazide. So in the present work we selected four different
aroylhydrazones as principal ligands. Introduction of heterocyclic bases like
1,10-phenanthroline, 2,2′-bipyridine, 3-picoline and pyridine leads to the
syntheses of mixed ligand metal chelates which can cause different bonding
modes, spectral properties and geometries in coordination compounds. The
importance of aroylhydrazones and their complexes in various fields and their
interesting coordinating properties stimulate our interest in the investigation of
transition metal chelates with four different aroylhydrazones. The aroylhydrazones
selected are 4-benzyloxy-2-hydroxybenzaldehyde-4-nitrobenzoylhydrazone
dimethylformamide monosolvate, 5-bromo-2-hydroxy-3-methoxybenzaldehyde
nicotinoylhydrazone dihydrate methanol monosolvate, 4-diethylamino-2-
hydroxybenzaldehyde nicotinoylhydrazone monohydrate and 2-benzoylpyridine-
4-nitrobenzoylhydrazone. The selection of 4-benzyloxy-2-hydroxybenzaldehyde-
4-nitrobenzoylhydrazone was based on the idea of developing ligands having
D-π-A general structure, so that the proligand and metal complexes exhibit
NLO activity. Hence it is interesting to explore the coordinating capabilities
of the synthesized hydrazones and to study the NLO activity of hydrazones
and some of the metal complexes.