The Sorption Properties And Energetic Heterogeneity Characterization Of Hgba2ca2cu3o8+ Sample By Means Of The Thermogravimetry
THE SORPTION PROPERTIES AND ENERGETIC HETEROGENEITY CHARACTERIZATION OF HgBa2Ca2Cu3O8+δ SAMPLE BY MEANS OF THE THERMOGRAVIMETRY
AND SORPTOMETRY TECHNIQUES
P. Staszczuk 1, D. Sternik 1, V.V. Kutarov 2, G.W. Chadzynski 3
1Department of Physicochemistry of Solid Surface, Chemistry Faculty
Maria Curie-Sklodowska University,
Maria Curie-Sklodowska sq. 3, 20-031 Lublin, Poland
2 Physical Research Institute, Odessa I.I. Mechnikov National University,
Pastera st. 27, 65026 Odessa, Ukraine
3 Telecommunications Research Institute, Wroclaw Devision,
Grabiszynska st. 97, 53-439 Wroclaw, Poland
Great number of physical and chemical processes takes place on surface bordering of phases, other processes are devised on them. From this of reason acquaintance of occurrences reaching on terminal surfaces has of principle meaning for explanations of mechanism investigated of processes, all the more, that often cause they changes of physicochemical properties. To most characteristic proprieties of solid surface belongs to her ability to adsorption steams and of gases. The cause this phenomena is fact, that forces acting within of crystal are only partly saturated on crystal surface. Therefore, the solid surface can absorb molecules from gas, liquid and even of solid phases.
The immersing of HgBa2Ca2Cu3O8+d sample with n-octane vapours in a vacuum dessicator, where p/p0 =1, blocks all adsorption active centers, the surface and capillary forces of the sample studied. The studies were made using simultaneous derivatograph Q-1500 D (MOM, Budapest, Hungary). The thermodesorption of n-octane measurements was carried out in quasi-isothermal condition in a temperature range of 20 – 250 0C with a furnance heating rate of 6 0C/min. The Q-TG and Q-DTG curves were registered digitally under the control of the program Derivat running on PC. Liquid thermodesorption under quasi-isothermal conditions depends on the adsorbate-adsorbate and adsorbate-adsorbent interaction. Specific surface areas, pore size and volume of the high temperature superconductor sample were calculated
from the low-temperature nitrogen adsorption isotherms measured by means of the sorptomat apparatus type ASAP 2405 V1.01 (Micrometrics Inc., USA).
A special technique of thermal analysis can be successfully applied for studies of solid surface heterogeneity including nonporous adsorbents like high-temperature superconductors. The presented results indicate clearly that the surface of HgBa2Ca2Cu3O8+d sample is energetically heterogeneous.
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