Cesare Oliva - Academia.edu (original) (raw)
Papers by Cesare Oliva
Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1988
Journal of Magnetic Resonance (1969), 1981
J. Chem. Soc., Faraday Trans., 1992
Page 1. J. CHEM. SOC. FARADAY TRANS., 1992, 88(7), 1041-1048 1041 Structural Analysis of some Alk... more Page 1. J. CHEM. SOC. FARADAY TRANS., 1992, 88(7), 1041-1048 1041 Structural Analysis of some Alkaline-earth-metal-Copper Oxide Catalysts for Hydrocarbon Oxidation or NO Decomposition Lucio Forni," Cesare Oliva and Francesco P. Vatti Dip. ...
Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1987
Page 1. J. Chem. SOC., Faraday Trans. I, 1987, 83 (IZ), 3717-3723 Single-crystal Proton ENDOR of ... more Page 1. J. Chem. SOC., Faraday Trans. I, 1987, 83 (IZ), 3717-3723 Single-crystal Proton ENDOR of the SO, Centre in y-Irradiated Sulphamic Acid Neil M. Atherton,* Cesare Oliva,? Elizabeth J. Oliver and Dugald M. Wylie Department ...
Journal of the Chemical Society, Faraday Transactions, 1990
Johnson Matthey Technology Review, 2014
To evaluate future applications of metallic clusters in nanoscience and nanotechnology, the elect... more To evaluate future applications of metallic clusters in nanoscience and nanotechnology, the electronic properties of the high-nuclearity carbonyl anionic platinum cluster [Pt 19 (CO) 22 ] 4were investigated using two different organic cations. In particular, N,N'-diethyl viologen dication (Vio 2+) and N,N'-dimethyl-9,9'-bis-acridinium dication (Acr 2+) were employed as counterions, oxidising agents and characterisation probes. The reactions of [Pt 19 (CO) 22 ] 4tetra-n-butylammonium salt, (TBA +) 4 ([Pt 19 (CO) 22 ] 4-), with both (Vio 2+) and (Acr 2+), used as tetraphenylborate salts, yielded two new compounds, which were isolated. The stoichiometries and properties of these new compounds were determined and compared on the basis of infrared (IR) solution spectra, electron spin resonance (ESR) analyses, fl uorometric spectra, superconducting quantum interference device (SQUID) magnetometry and resistivity measurements. For Vio 2+ , a cation-exchange reaction produced the fi nal compound (Vio 2+) 2 ([Pt 19 (CO) 22 ] 4-), 'PtVio', which was structurally characterised by single crystal X-ray diffraction (XRD) analysis. However, when using Acr 2+ , a spontaneous redox reaction occurred and a (Acr +)(TBA +) 2 ([Pt 19 (CO) 22 ] 3-) stoichiometry for the precipitated solid, 'PtAcr', was inferred from the experimental evidence, leading to an interesting 'doubly-radicalic salt'. This new type of salt, consisting of a radical anionic Pt cluster and a radical cation, is characterised by extremely simple synthesis and isolation processes and by the lowest solid-state resistivity found in high-nuclearity cluster salts with redox-active cations (1).
Physical Chemistry Chemical Physics, 1999
EPR analysis of (M= Ce, Eu, Sr) perovskitic La 1x M x MnO 3'y catalysts for methane oxidati... more EPR analysis of (M= Ce, Eu, Sr) perovskitic La 1x M x MnO 3'y catalysts for methane oxidation¤ Cesare Oliva,a* Lucio Forni,a Paolo Pasqualin,a Andrea DÏAmbrosioa and Anatoli V. Vishniakovb a Dipartimento di Chimica Fisica ed Elettrochimica e Centro CNR CSRSRC, ...
Journal of Solid State Chemistry, 2004
EPR analysis is carried out with Ce1−xGdxO(4−x)/2 (x=0.1; 0.2) nanopowders aiming at obtaining in... more EPR analysis is carried out with Ce1−xGdxO(4−x)/2 (x=0.1; 0.2) nanopowders aiming at obtaining information about their oxidation and reduction properties. The EPR spectrum of these systems is composed of a single feature. The first derivative peak-to-peak spectral intensity decreases at higher temperatures, but this trend deviates from that of Curie's law with the x=0.1 sample, at difference with the x=0.2
Journal of Materials Chemistry, 2001
Poly(ethylene terephthalate) (PET) and cotton fibres, treated in an appositely set up RF SF6 plas... more Poly(ethylene terephthalate) (PET) and cotton fibres, treated in an appositely set up RF SF6 plasma reactor under different operating conditions, were characterised by XPS, EPR, DSC, XRD, ATR analyses, water contact angle and water droplet roll-off angle measurements. The ageing ...
Catalysis Today, 2011
Pure and N-doped TiO2 nanoparticles are obtained by a combination of wet and thermal procedures, ... more Pure and N-doped TiO2 nanoparticles are obtained by a combination of wet and thermal procedures, starting from TiCl3 and alkoxide precursors; the N-source is both inorganic (NH3) and organic (triethylamine). Samples are characterized for their bulk, surface, optical and magnetic properties. Ab initio calculations of the electronic properties of the doped samples are performed. Sample thin films are tested for
Catalysis Communications, 2000
Four dierent LaMnO 3 perovskites were prepared by dierent procedures, characterised and tested fo... more Four dierent LaMnO 3 perovskites were prepared by dierent procedures, characterised and tested for the catalytic ameless combustion of methane. EPR and XRD have been found useful probes for testing activity and durability of the catalysts, respectively. Broader EPR lines correspond to more active catalysts, while high crystallinity indicates long-lived samples.
Relations between structure and physical properties in REBa2Cu3O6+d (RE-123) High Temperature Sup... more Relations between structure and physical properties in REBa2Cu3O6+d (RE-123) High Temperature Superconductors (RE = Y, Ln; 0 < d < 1) are not fully understood. As an example, the effect of long range or local Cu-O chain ordering on the superconducting properties has still to be unambiguously probed by experiment [1]. A suitable way to handle this problem is to perform cation substitutions for copper in RE-123 and study the physical and structural properties of the doped materials. Aluminium seems to be an optimal substituent as it is a non-magnetic ion and it substitutes for copper only on one of the two crystallographic non-equivalent positions, Cu1 (0,0,0) [2]. As a part of a wider study on the relation between the short/long range structure and the physical properties of Al doped REBa2Cu3O6+d, the attention in the present work is focused on the structural disorder induced by Al-doping in SmBa2Cu3-xAlxO6+d\uf02e\uf020 For this purpose samples of SmBa2Cu3-xAlxO6+d\uf02e\uf020\uf0280< d < 1, x = 0, 0.15, 0.33) have been investigated by means of X-ray Powder Diffraction (XRPD) at the ID31 beamline of the European Synchrotron Radiation Facility, as a function of aluminium concentration, oxygen non-stoichiometry d and temperature. The XRPD data have been refined also in real space through the analysis of the pair distribution function (PDF) thanks to the high counting statistics and to the wide Q range (Qmax ~ 18 \uc5-1). In highly doped samples the tetragonal-to-orthorhombic phase transition is inhibited because the local tetrahedral environment for Aluminium inhibits the formation of long Cu-O chains while oxidising. The actual length of Cu-O chains (at d ~ 1) is a function of both aluminium concentration and clustering. The aluminium insertion induces local disorder due to heavy ion displacements as it can be evaluated comparing the atomic thermal factors (Uiso) of doped and undoped samples and by the PDF analysis
Journal of Molecular Catalysis A: Chemical, 2006
Sr1-x Mx TiO3 (x = 0 or 0.1; M = K or Gd) have been compared as catalysts for the flameless com... more Sr1-x Mx TiO3 (x = 0 or 0.1; M = K or Gd) have been compared as catalysts for the flameless combustion of methane. The samples were prepared both by traditional sol-gel (SG) and by flame-hydrolysis (FH) procedure. All the catalysts possessed the perovskite-like structure, with some SrCO3 as impurity with Sr0.9K0.1TiO3 prepared by SG procedure. All the samples prepared by FH were better catalysts than those prepared by SG. A further improvement in the catalytic activity was obtained with M = K, but only at temperatures lower than 550°C. X-band and Q-band EPR spectroscopies provided an explanation of this observation, based on the high mobility of surface O3species on the surface of the (FH) Sr0.9K0.1TiO3 sample.
Solid State Phenomena, 2007
... e-mail: a kruk_s@mail.ru, b avish@muctr.edu.ru, c lucio.forni@unimi.it, d cesare.oliva@unimi.... more ... e-mail: a kruk_s@mail.ru, b avish@muctr.edu.ru, c lucio.forni@unimi.it, d cesare.oliva@unimi. it Keywords: perovskite, flame-spray pyrolysis, catalytic methane combustion, ... Noble metals, especially Pd, are known to be the most active catalysts for methane flameless combustion. ...
Physical Review B, 2015
We report on the structural, electronic, and magnetic phases of a previously unexplored region in... more We report on the structural, electronic, and magnetic phases of a previously unexplored region in the phase diagram of GdBaCo 2 O 5+δ (δ = 0.57 and 0.63). Despite a homogenous average structure displayed by both the samples, the orthorhombic highly oxygenated GdBaCo 2 O 5.63 shows clear signatures of structural nanoscale phase separation. By combining a pair distribution function with photoluminescence and electron spin resonance techniques, we found that the nanoscale phase separation is induced by an inhomogeneous distribution of ferromagnetic Co 3+ − Co 4+ clusters embedded in an antiferromagnetic Co 3+-rich matrix. In addition, we uncovered a phase evolution involving the collapse of the orthorhombic strain below room temperature. The origin of this noncanonical transition seems to be associated with the interplay of the observed nanoscale phase separation and a new magnetic phase transition occurring below T ∼ 180 K.
Zeitschrift für Kristallographie Supplements, 2007
In the present work the structural effects of La 2 CuO 4 doping with CeO 2 , or of supporting the... more In the present work the structural effects of La 2 CuO 4 doping with CeO 2 , or of supporting the former on the latter, have been investigated. It was found that lanthanum oxide possesses a very good solubility in cerium dioxide in the presence of copper oxide, forming a solid solution. According to our experimental data, at 1050°C and in the presence of copper oxide (over 1.5% mass), the boundary for the existence of the Ce 19z La z O 29z /29C phase falls between z "0.398 and z "0.462. Copper oxide itself has a very low, but appreciable solubility in this system. The excess of CuO strongly increases the rate of formation of the solid oxides solution, due to its relatively low melting point.
Journal of Spectroscopy, 2015
A combined electron spin resonance (ESR) and atomic force microscopy (AFM) study on Ce1−xGdxO2−x/... more A combined electron spin resonance (ESR) and atomic force microscopy (AFM) study on Ce1−xGdxO2−x/2samples is here presented, aimed at investigating the evolution of the ESR spectral shape as a function ofxin a wide composition range. At lowx=0.02, the spectrum is composed of features atgeff≈2; 2.8; 6. With increasingx, this pattern merges into a singlegeff≈2broad ESR curve, which assumes a Dysonian-shaped profile atx≥0.5, whereas, at thesexvalues, AFM measurements show an increasing surface roughness. It is suggested that the last could cause the formation of surface polaritons at the origin of the particular ESR spectral profile observed at these high Gd doping levels.
Journal of the Chemical Society, Faraday Transactions, 1990
Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1988
Journal of Magnetic Resonance (1969), 1981
J. Chem. Soc., Faraday Trans., 1992
Page 1. J. CHEM. SOC. FARADAY TRANS., 1992, 88(7), 1041-1048 1041 Structural Analysis of some Alk... more Page 1. J. CHEM. SOC. FARADAY TRANS., 1992, 88(7), 1041-1048 1041 Structural Analysis of some Alkaline-earth-metal-Copper Oxide Catalysts for Hydrocarbon Oxidation or NO Decomposition Lucio Forni," Cesare Oliva and Francesco P. Vatti Dip. ...
Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases, 1987
Page 1. J. Chem. SOC., Faraday Trans. I, 1987, 83 (IZ), 3717-3723 Single-crystal Proton ENDOR of ... more Page 1. J. Chem. SOC., Faraday Trans. I, 1987, 83 (IZ), 3717-3723 Single-crystal Proton ENDOR of the SO, Centre in y-Irradiated Sulphamic Acid Neil M. Atherton,* Cesare Oliva,? Elizabeth J. Oliver and Dugald M. Wylie Department ...
Journal of the Chemical Society, Faraday Transactions, 1990
Johnson Matthey Technology Review, 2014
To evaluate future applications of metallic clusters in nanoscience and nanotechnology, the elect... more To evaluate future applications of metallic clusters in nanoscience and nanotechnology, the electronic properties of the high-nuclearity carbonyl anionic platinum cluster [Pt 19 (CO) 22 ] 4were investigated using two different organic cations. In particular, N,N'-diethyl viologen dication (Vio 2+) and N,N'-dimethyl-9,9'-bis-acridinium dication (Acr 2+) were employed as counterions, oxidising agents and characterisation probes. The reactions of [Pt 19 (CO) 22 ] 4tetra-n-butylammonium salt, (TBA +) 4 ([Pt 19 (CO) 22 ] 4-), with both (Vio 2+) and (Acr 2+), used as tetraphenylborate salts, yielded two new compounds, which were isolated. The stoichiometries and properties of these new compounds were determined and compared on the basis of infrared (IR) solution spectra, electron spin resonance (ESR) analyses, fl uorometric spectra, superconducting quantum interference device (SQUID) magnetometry and resistivity measurements. For Vio 2+ , a cation-exchange reaction produced the fi nal compound (Vio 2+) 2 ([Pt 19 (CO) 22 ] 4-), 'PtVio', which was structurally characterised by single crystal X-ray diffraction (XRD) analysis. However, when using Acr 2+ , a spontaneous redox reaction occurred and a (Acr +)(TBA +) 2 ([Pt 19 (CO) 22 ] 3-) stoichiometry for the precipitated solid, 'PtAcr', was inferred from the experimental evidence, leading to an interesting 'doubly-radicalic salt'. This new type of salt, consisting of a radical anionic Pt cluster and a radical cation, is characterised by extremely simple synthesis and isolation processes and by the lowest solid-state resistivity found in high-nuclearity cluster salts with redox-active cations (1).
Physical Chemistry Chemical Physics, 1999
EPR analysis of (M= Ce, Eu, Sr) perovskitic La 1x M x MnO 3'y catalysts for methane oxidati... more EPR analysis of (M= Ce, Eu, Sr) perovskitic La 1x M x MnO 3'y catalysts for methane oxidation¤ Cesare Oliva,a* Lucio Forni,a Paolo Pasqualin,a Andrea DÏAmbrosioa and Anatoli V. Vishniakovb a Dipartimento di Chimica Fisica ed Elettrochimica e Centro CNR CSRSRC, ...
Journal of Solid State Chemistry, 2004
EPR analysis is carried out with Ce1−xGdxO(4−x)/2 (x=0.1; 0.2) nanopowders aiming at obtaining in... more EPR analysis is carried out with Ce1−xGdxO(4−x)/2 (x=0.1; 0.2) nanopowders aiming at obtaining information about their oxidation and reduction properties. The EPR spectrum of these systems is composed of a single feature. The first derivative peak-to-peak spectral intensity decreases at higher temperatures, but this trend deviates from that of Curie&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#x27;s law with the x=0.1 sample, at difference with the x=0.2
Journal of Materials Chemistry, 2001
Poly(ethylene terephthalate) (PET) and cotton fibres, treated in an appositely set up RF SF6 plas... more Poly(ethylene terephthalate) (PET) and cotton fibres, treated in an appositely set up RF SF6 plasma reactor under different operating conditions, were characterised by XPS, EPR, DSC, XRD, ATR analyses, water contact angle and water droplet roll-off angle measurements. The ageing ...
Catalysis Today, 2011
Pure and N-doped TiO2 nanoparticles are obtained by a combination of wet and thermal procedures, ... more Pure and N-doped TiO2 nanoparticles are obtained by a combination of wet and thermal procedures, starting from TiCl3 and alkoxide precursors; the N-source is both inorganic (NH3) and organic (triethylamine). Samples are characterized for their bulk, surface, optical and magnetic properties. Ab initio calculations of the electronic properties of the doped samples are performed. Sample thin films are tested for
Catalysis Communications, 2000
Four dierent LaMnO 3 perovskites were prepared by dierent procedures, characterised and tested fo... more Four dierent LaMnO 3 perovskites were prepared by dierent procedures, characterised and tested for the catalytic ameless combustion of methane. EPR and XRD have been found useful probes for testing activity and durability of the catalysts, respectively. Broader EPR lines correspond to more active catalysts, while high crystallinity indicates long-lived samples.
Relations between structure and physical properties in REBa2Cu3O6+d (RE-123) High Temperature Sup... more Relations between structure and physical properties in REBa2Cu3O6+d (RE-123) High Temperature Superconductors (RE = Y, Ln; 0 < d < 1) are not fully understood. As an example, the effect of long range or local Cu-O chain ordering on the superconducting properties has still to be unambiguously probed by experiment [1]. A suitable way to handle this problem is to perform cation substitutions for copper in RE-123 and study the physical and structural properties of the doped materials. Aluminium seems to be an optimal substituent as it is a non-magnetic ion and it substitutes for copper only on one of the two crystallographic non-equivalent positions, Cu1 (0,0,0) [2]. As a part of a wider study on the relation between the short/long range structure and the physical properties of Al doped REBa2Cu3O6+d, the attention in the present work is focused on the structural disorder induced by Al-doping in SmBa2Cu3-xAlxO6+d\uf02e\uf020 For this purpose samples of SmBa2Cu3-xAlxO6+d\uf02e\uf020\uf0280< d < 1, x = 0, 0.15, 0.33) have been investigated by means of X-ray Powder Diffraction (XRPD) at the ID31 beamline of the European Synchrotron Radiation Facility, as a function of aluminium concentration, oxygen non-stoichiometry d and temperature. The XRPD data have been refined also in real space through the analysis of the pair distribution function (PDF) thanks to the high counting statistics and to the wide Q range (Qmax ~ 18 \uc5-1). In highly doped samples the tetragonal-to-orthorhombic phase transition is inhibited because the local tetrahedral environment for Aluminium inhibits the formation of long Cu-O chains while oxidising. The actual length of Cu-O chains (at d ~ 1) is a function of both aluminium concentration and clustering. The aluminium insertion induces local disorder due to heavy ion displacements as it can be evaluated comparing the atomic thermal factors (Uiso) of doped and undoped samples and by the PDF analysis
Journal of Molecular Catalysis A: Chemical, 2006
Sr1-x Mx TiO3 (x = 0 or 0.1; M = K or Gd) have been compared as catalysts for the flameless com... more Sr1-x Mx TiO3 (x = 0 or 0.1; M = K or Gd) have been compared as catalysts for the flameless combustion of methane. The samples were prepared both by traditional sol-gel (SG) and by flame-hydrolysis (FH) procedure. All the catalysts possessed the perovskite-like structure, with some SrCO3 as impurity with Sr0.9K0.1TiO3 prepared by SG procedure. All the samples prepared by FH were better catalysts than those prepared by SG. A further improvement in the catalytic activity was obtained with M = K, but only at temperatures lower than 550°C. X-band and Q-band EPR spectroscopies provided an explanation of this observation, based on the high mobility of surface O3species on the surface of the (FH) Sr0.9K0.1TiO3 sample.
Solid State Phenomena, 2007
... e-mail: a kruk_s@mail.ru, b avish@muctr.edu.ru, c lucio.forni@unimi.it, d cesare.oliva@unimi.... more ... e-mail: a kruk_s@mail.ru, b avish@muctr.edu.ru, c lucio.forni@unimi.it, d cesare.oliva@unimi. it Keywords: perovskite, flame-spray pyrolysis, catalytic methane combustion, ... Noble metals, especially Pd, are known to be the most active catalysts for methane flameless combustion. ...
Physical Review B, 2015
We report on the structural, electronic, and magnetic phases of a previously unexplored region in... more We report on the structural, electronic, and magnetic phases of a previously unexplored region in the phase diagram of GdBaCo 2 O 5+δ (δ = 0.57 and 0.63). Despite a homogenous average structure displayed by both the samples, the orthorhombic highly oxygenated GdBaCo 2 O 5.63 shows clear signatures of structural nanoscale phase separation. By combining a pair distribution function with photoluminescence and electron spin resonance techniques, we found that the nanoscale phase separation is induced by an inhomogeneous distribution of ferromagnetic Co 3+ − Co 4+ clusters embedded in an antiferromagnetic Co 3+-rich matrix. In addition, we uncovered a phase evolution involving the collapse of the orthorhombic strain below room temperature. The origin of this noncanonical transition seems to be associated with the interplay of the observed nanoscale phase separation and a new magnetic phase transition occurring below T ∼ 180 K.
Zeitschrift für Kristallographie Supplements, 2007
In the present work the structural effects of La 2 CuO 4 doping with CeO 2 , or of supporting the... more In the present work the structural effects of La 2 CuO 4 doping with CeO 2 , or of supporting the former on the latter, have been investigated. It was found that lanthanum oxide possesses a very good solubility in cerium dioxide in the presence of copper oxide, forming a solid solution. According to our experimental data, at 1050°C and in the presence of copper oxide (over 1.5% mass), the boundary for the existence of the Ce 19z La z O 29z /29C phase falls between z "0.398 and z "0.462. Copper oxide itself has a very low, but appreciable solubility in this system. The excess of CuO strongly increases the rate of formation of the solid oxides solution, due to its relatively low melting point.
Journal of Spectroscopy, 2015
A combined electron spin resonance (ESR) and atomic force microscopy (AFM) study on Ce1−xGdxO2−x/... more A combined electron spin resonance (ESR) and atomic force microscopy (AFM) study on Ce1−xGdxO2−x/2samples is here presented, aimed at investigating the evolution of the ESR spectral shape as a function ofxin a wide composition range. At lowx=0.02, the spectrum is composed of features atgeff≈2; 2.8; 6. With increasingx, this pattern merges into a singlegeff≈2broad ESR curve, which assumes a Dysonian-shaped profile atx≥0.5, whereas, at thesexvalues, AFM measurements show an increasing surface roughness. It is suggested that the last could cause the formation of surface polaritons at the origin of the particular ESR spectral profile observed at these high Gd doping levels.
Journal of the Chemical Society, Faraday Transactions, 1990