عنوان مقاله [English]
In this research, a chemical getter with 75%wt zirconium, 22% cobalt, 1.5%wt of praseodymium and 1.5%wt neodymium was synthesized by ball milling. The effect of these elements on the adsorption/desorption properties of the getter was compared with the effect of yttrium. Due to the high activity of non-evaporable getters, oxide layers are formed on the surface. So, for activating a getter these layers must be removed. For this purpose, the samples were first placed at 100 °C for 30 minutes and then were activated at 360 °C for 80 minutes. The results of the adsorption tests in terms of pressure and temperature variations versus time indicated that the activation temperature for the yttrium sample was reduced by about 60 degrees and reached from 260 to 200 °C. The start pressure of the adsorption test in the getter chamber for all samples is 1.5 × 10-5 mmHg. While in the case of Y the final pressure of the reactor was reached to 1.3 × 10-6 mmHg. After completion of the activation process, the connection between the reactor and the vacuum pumps was disconnected to determine the time of vacuum preserving from 0.001 to 0.2 mmHg. The required time to break the vacuum for yttrium containing sample was 4955 seconds, which has the highest value. According to the results, the performance of the Pr, Nd and Y is close to each other, and all of the these elements reduced the pressure of the system by about ten times and increased the vacuum breaking time to more than 4000 seconds.
1. A, P., Non-evaporable getter thin film coatings for vacuum applications. Metrial engineering, 2002: p. 185.
2. Prodromides, A., Non-evaporable getter thin film coatings for vacuum applications. 2002, Ingénieur diplômée de l’ENSI de Caen, DEA en sciences des matériaux, Université de Caen, France et de nationalité française.
3. Lafferty, J.M., Foundations of vacuum science and technology. Vacuum Science and Technology. 2003. 262-268.
4. Coda Alberto, C.A., Toia luca, Bovisio. magda, Baronio. Paola, Non-evaporable getter alloys based on yttrium for hydrogen sorption., in vacuum. 2008. p. 37-43.
5. Benvenuti, C., Molecular Surface Pumping: the Getter Pump. Vacuum Technology, June 1999(Proceedings of the CERN Accelerator School, Scanticon Conference Centre): p. 99-105.
6. Yong Hwan Kim, R.O.S., Hiroshi Numakura, Hirobumi Wada, Katsutoshi Ono, Removal of oxygen and nitrogen from niobium by external gettering. Journal of alloys and compounds, 1997. 248(1-2): p. 251-258.
7. P.Roupcova, O.S., Changes in phase composition of Zr–Fe–V getter after hydriding and vacuum dehydriding cycles. Journal of alloys and compounds, 2002. 492(1-2): p. 160-165.
8. Matolin. V, D.V., Fabik.S, Chab.V, Masek.K, Matolinova. I, Prince. K.C, Skala.T, Sutara. F, Tsud. N, Veltruska.K, Activation of binary Zr–V non-evaporable getters: synchrotron radiation photoemission study. Applied surface science. 243(1-4): p. 106-112.
9. J.F. Fana, C.L.Y., G. Hana, S. Fanga, W.D. Yang, B.S. Xua, Oxidation behavior of ignition-proof magnesium alloys with rare earth addition. Journal of Alloys and Compounds, 2011. 509: p. 2137-2142.
10. A. Heidary Moghadam , V.D., A. Kaflou , H. Yoozbashizadeh, Development of a nanostructured Zr3Co intermetallic getter powder with enhanced pumping characteristics. Intermetallics. 2015. (57): p. 51-59.
11. Steve D Barrett, S.S.D., The Structure of Rare–Earth Metal Surfaces. 2001, BarrettUniversity of Liverpool.
12. a, D.C., et al., Structural, electronic and thermodynamic properties of ZrCo and ZrCoH3: A first-principles study. international Journal of hydrogen energy 2012. 37.
13. Bu, J.G., et al., Preparation and sorption characteristics of Zr–Co–RE getter films. Journal of Alloys and Compounds 2012. 529: p. 69– 72.
14. A. Heidary Moghadam a, V.D.b., A. Kaflou b, H. Yoozbashizadeh a, R. Ashiri, Development of a nanostructured Zr3Co intermetallic getter powder with enhanced pumping characteristics. Intermetallics, 2015. 57: p. 51-59.
15. A. Heidary Moghadam , V.D., A. Kaflou , H. Yoozbashizadeh, Effect of rare earth elements on sorption characteristics of nanostructured Zr-Co sintered porous getters in Material engineering department. 2015, Olom tahghighat university. p. 145.
16. A. Heidary Moghadam , V.D., A. Kaflou , H. Yoozbashizadeh, Effect of rare earth elements on sorption characteristics of nanostructured Zr-Co sintered porous getters. Vacuum, 2015. 111: p. 9-14.
17. Dean, J., Lange’s Handbook of Chemistry, ed. 11. 1979, McGraw-Hill: New York.
18. Ellingham Diagram for Selected Oxides, Data from Thomas B. Reed, Free Energy of Formation of Binary Compounds, MIT Press, Cambridge, MA, 1971.
19. Bakker, H., Bonzel, H.P., Bruff, C.M., Dayananda, M.A., Gust, W., Horvath, J., Kaur, I., Kidson, G.V., LeClaire, A.D., Mehrer, H., Murch, G.E., Neumann, G., Stolica, N., Stolwijk, N.A. , Diffusion in solid metals and alloys. Condensed Matter, 1990. 26.