Decomposition Of Silver Oxalate Research Articles

Paramagnetic behaviour of silver nanoparticles generated by decomposition of silver oxalate

Silver oxalate Ag2C2O4, was already proposed for soldering applications, due to the formation when it is decomposed by a heat treatment, of highly sinterable silver nanoparticles. When slowly decomposed at low temperature (125 °C), the oxalate leads however to silver nanoparticles isolated from each other. As soon as these nanoparticles are formed, the magnetic susceptibility at room temperature increases from −3.14 10−7 emu.Oe−1.g−1 (silver oxalate) up to −1.92 10−7 emu.Oe−1.g−1 (metallic silver). At the end of the oxalate decomposition, the conventional diamagnetic behaviour of bulk silver, is observed from room temperature to 80 K. A diamagnetic-paramagnetic transition is however revealed below 80 K leading at 2 K, to silver nanoparticles with a positive magnetic susceptibility. This original behaviour, compared to the one of bulk silver, can be ascribed to the nanometric size of the metallic particles.

Microwave-assisted rapid synthesis of anisotropic Ag nanoparticles by solid statetransformation

Anisotropic silver nanoparticles (NPs) have been synthesized rapidly using microwaveirradiation by the decomposition of silver oxalate in a glycol medium using polyvinylpyrolidone (PVP) as the capping agent. The obtained Ag nanoparticles havebeen characterized by UV–visible spectroscopy, powder x-ray diffraction (XRD),transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) studies.Anisotropic Ag nanoparticles of average size around 30 nm have been observed in thecase of microwave irradiation for 75 s whereas spherical particles of a size around5–6 nm are formed for 60 s of irradiation. The texture coefficient and particle sizecalculated from XRD patterns of anisotropic nanoparticles reveal the preferentialorientation of (111) facets in the Ag sample. Ethylene glycol is found to be amore suitable medium than diethylene glycol. A plausible mechanism has beenproposed for the formation of anisotropic Ag nanoparticles from silver oxalate.

Carbon solubility in Mid-Ocean Ridge basaltic melt at low pressures (250–1950 bar)

The carbon solubility in a Mid-Ocean Ridge Basaltic (MORB) melt was determined by equilibrating natural glass with CO 2 produced by decomposition of silver oxalate. These experiments were performed in closed platinum capsules in an internally heated pressure vessel at 1200 and 1300°C, at oxygen fugacity close to the QFM buffer and at pressures between 250 and 1950 bar. Carbon was extracted by incremental heating to fusion and determined by manometry after oxidation to CO 2. This method separates small contributions from bubbles trapped in the experimental melts and extracts all the dissolved carbon regardless of its chemical form. Linear correlation between total dissolved C and the total pressure was observed, confirming that carbon solubility obeys Henry's law in the range 0–2000 bar. This yields a best fit minimum solubility of 0.137 ± 0.004 ppm C/bar which can be applied to MORB at crustal pressures. These experimental glasses, measured by FTIR for carbonate ion absorptions, provide a new determination of the CO 3 2− molar absorption coefficient (ε = 398 ± 10 l mol −1 cm −1) in perfect agreement with an independent natural sample calibration (ε = 397 ± 7 l mol −1 cm −1). Comparison to results from literature dissolved C contents of MORB glasses confirms that many are supersaturated at eruption as a result of slow kinetics of degassing, while a few others are undersaturated because of either C loss during degassing of water-rich melts or generation from carbon-poor sources.

Decomposition of Silver Oxalate. I. Microscopic Observations of Partially Decomposed Crystals

Decomposition of Silver Oxalate. I. Microscopic Observations of Partially Decomposed Crystals

Effect of additives on physico-chemical properties of silver oxalate, photolysis, radiolysis and thermal decomposition of silver oxalate

Effect of additives on physico-chemical properties of silver oxalate, photolysis, radiolysis and thermal decomposition of silver oxalate

The decomposition of silver oxalate

The decomposition of silver oxalate

New experiments on the thermal decomposition of silver oxalate

New experiments on the thermal decomposition of silver oxalate

54. The temperature coefficient of the thermal decomposition of silver oxalate

54. The temperature coefficient of the thermal decomposition of silver oxalate

CCCLXXX.—The formation and growth of silver nuclei in the decomposition of silver oxalate

CCCLXXX.—The formation and growth of silver nuclei in the decomposition of silver oxalate