Responsible staff member:

Dr. Andrea Orlando (CNR Researcher)

People:

Dr. Daniele Borrini (University of  Florence)

Prof. Sandro Conticelli (University of  Florence)

Telephone Numbers:

055 2757510

055 2757499

E-mail:

Dr. Andrea Orlando:  This e-mail address is being protected from spambots. You need JavaScript enabled to view it

Dr. Daniele Borrini:  This e-mail address is being protected from spambots. You need JavaScript enabled to view it

The WC piston (1) supported by a ram is visible in the lower part. Above, the counteracting ram (2) which provides the end-load to the pressure chamber (3)

Instruments:

• Furnaces: These are mainly chamber furnaces (Carbolite ELF 10/14, CSF 1200 and CWF 1200), attaining 1200°C, and an horizontal tubular furnace (Carbolite STF 15/50/450) up to 1500°C equipped with quenching device. They are used for thermal treatments at ambient pressure of samples as well as for pre-treatment of starting materials for high pressure experiments..

• Vertical quench furnace: It is a Deltech DT-31 consisting of a vertical alumina tube surrounded by molydisilicide heating elements. Temperature (up to 1650°C) is controlled by two B-type thermocouples and the actual sample temperature can be monitored by an additional S-type thermocouple. The sample can be contained in a Pt crucible or hosted on a Pt wire loop and it is suspended in the hot spot by means of a thin Pt wire connected to two thick Pt quenching electrodes. At the end of the experiment rapid quench is attained by melting the thin Pt wire via a current flow through electrodes; the sample drops at the bottom of the furnace into a quenching pot filled with water or liquid nitrogen. Oxygen fugacity control during the experiments is possible by means of a mixture of two gases (CO and CO₂) flowing through the furnace tube. Applications: phase relations of natural and synthetic systems at atmospheric pressure, preparation of glass as starting material in high pressure experiments. ).

• Externally heated apparatus: It is a two-units instrument of Leco Corp. (model HR-2B-2). The René 41 pressure vessels are closed in the upper end by cone-in-cone seals which always remain outside of the furnace (hence cold-seal) and allow the pressure medium (water) to enter/exit vessels. They are positioned into sliding dual-zone type vertical furnaces, thus enabling a thermal gradient to be established and monitored. The sample (up to several grams) is loaded into a sealed noble metal capsule (generally Au) and kept in the lower end of the vessel by a solid alumina or steel rod. Pressure (up to 0.4 GPa) is measured by pressure gauges while temperature (up to 900°C) is controlled and monitored by K-type thermocouples. Applications: phase relations of natural and synthetic systems in P-T conditions pertaining to the upper crust.

• Piston cylinder apparatus: It consists of a 0.5" WC piston pressing into a steel cylinder (pressure chamber) whose core is formed by WC too. The cylinder hosts an assembly constituted by different materials and containing the sample capsule. The piston is driven by a 75 tonnes lower ram while a 100 tonnes upper ram provides extra force to end load the pressure chamber. The actual pressure acting on the sample can vary from 0.5 to 3.0 GPa. Temperature (up to 1700°C) is generated by a very high intensity (500 amps) low voltage (6 volts) current through a graphite furnace (part of the assembly) and is controlled by a S-type thermocouple.

Related Pubblications:

Bonazzi P., Borrini D., Mazzi F. & Olmi F. (1995): Crystal structure and twinning of Sb2AsS2, the synthetic analogue of paakkonenite. Am. Mineral., 80, 1054-1058.

Bernardini G.P., Borrini D., Corsini F., Danti C., Guarini G.G.T., Mazzetti G. & Rosso F.(1996): Thermal behaviour and kinetics of formation reaction of the synthetic analogue of paakkonenite, Sb2AsS2. Eur. J. Mineral., 8, 639-648.

Rosso F., Bernardini G.P., Borrini D., Danti C., Guarini G.G.T. & Mazzetti G. (1996): Estimation of rate coefficients from the overall amount of material reacted at various scan rates. Thermochimica Acta, 287, 327-342.

Bernardini G.P., Borrini D., Corsini F., Danti C. & Mazzetti G. (1997): Phase relations in the pseudobinary system Sb2S3 (stibnite)-Sb2As3 (stibarsen). N. Jb. Miner. Mh., 1997, 185-192.

Orlando A., Conticelli S., Armienti P. & Borrini D. (2000): Experimental study on a basanite from McMurdo Volcanic Group, Antarctica: inference on its mantle source. Antarctic Science, 12, 105-116.

Orlando A., Thibault Y. & Edgar A.D. (2000): Experimental study on wadeite-K2TiSi3O9 system between 2 and 3 GPa and its relation to the presence of phlogopite. Contrib. Mineral. Petrol., 139, 136-145.

Orlando A. & Borrini D. (2001): Solubility of Ti in andradite under upper mantle conditions: preliminary results. Periodico di Mineralogia, 70, 99-110.

Orlando A. & Borrini D. (2003): Synthesis of pyrope - grossular garnets: an experimental study at P=2.5 GPa. Mineral. and Petrol., 78, 37-51.