VUV 이오나이저용 Ca-Sr-Ba계 산화물 캐소드에 낮은 일함수를 갖는 금속산화물 첨가의 영향

박승규; 이종혁; 김란희; 정주형; 한완규; 이수현; 전성우; 김대준; 김도윤; 이광섭; Seung-Kyu Park; Jonghyuk Lee; Ran Hee Kim; Juhyoung Jung; Wan Gyu Han; Soo Huan Lee; Sung Woo Jeon; Dae Jun Kim; Do-Yun Kim2; Kwang-Sup Lee

Korean Journal of Materials Research, Vol.29, No.4, 241-251, April, 2019

DOI10.3740/MRSK.2019.29.4.241 Export Citation

VUV 이오나이저용 Ca-Sr-Ba계 산화물 캐소드에 낮은 일함수를 갖는 금속산화물 첨가의 영향

Effects on Addition of Metal Oxides with Low Workfunctions on the Ca-Sr-Ba Oxide Cathodes for VUV Ionizers

박승규, 이종혁, 김란희, 정주형, 한완규, 이수현, 전성우, 김대준¹, 김도윤¹, 이광섭^†

한남대학교 화공신소재공학과
¹㈜브이에스아이

Seung-Kyu Park, Jonghyuk Lee, Ran Hee Kim, Juhyoung Jung, Wan Gyu Han, Soo Huan Lee, Sung Woo Jeon, Dae Jun Kim¹, Do-Yun Kim2¹, and Kwang-Sup Lee^†

Department of Advanced Materials and Chemical Engineering, Hannam University, 1646 Yuseongdae-ro, Yuseong-Ku, Daejeon 34054, Republic of Korea
¹VSI Co. Ltd., 151-33 Namsuk-ro, Cheongju, Chungcheongbuk-do 28182, Republic of Korea

E-mail:

There are several manufacturing techniques for developing thermionic cathodes for vacuum ultraviolet(VUV) ionizers. The triple alkaline earth metal emitters(Ca-Sr-Ba) are formulated as efficient and reliable thermo-electron sources with a great many different compositions for the ionizing devices. We prepare two basic suspensions with different compositions: calcium, strontium and barium. After evaluating the electron-emitting performance for europium, gadolinium, and yttrium-based cathodes mixed with these suspensions, we selected the yttrium for its better performance. Next, another transition metal indium and a lanthanide metal neodymium salt is introduced to two base emitters. These final composite metal emitters are coated on the tungsten filament and then activated to the oxide cathodes by an intentionally programmed calcination process under an ultra-high vacuum(~10-6 torr). The performance of electron emission of the cathodes is characterized by their anode currents with respect to the addition of each element, In and Nd, and their concentration of cathodes. Compared to both the base cathodes, the electron emission performance of the cathodes containing indium and neodymium decreases. The anode current of the Nd cathode is more markedly degraded than that with In.

Keywords:ionizer;thermionic cathode;vacuum ultraviolet;metal oxides;work function

[References]

Lee DH, Choi DS, Jung YC, Kim SM, J. Korean Soc. Saf., 29, 34 (2014)
Chang JS, Berezin AA, J. Electrostat, 51-52, 64 (2001)
Inaba H, Ohmi T, Yoshida T, Okada T, J. Electrostat, 33, 15 (1994)
Liu QL, Chen DR, J. Aerosol Sci., 76, 148 (2014)
Herrmann IG, Wagener PS, The oxide coated cathode, p.1, Chapman and Hall Ltd., London, UK (1951).
Langmuir I, Phys. Rev., 22, 357 (1923)
Turner LW, Electronics Engineer's Reference Book, 4th ed., p.7, Newnes-Butterworth, London, England (1976).
Herrmann IG, Wagener PS, The oxide coated cathode, p.218, Chapman and Hall Ltd., London, UK, (1951).
Davis RF, BaO-CaO-Al2O3 Glass compositions, US Patent 3,852,079 (1974).
Dong L, Wang J, Liu W, Li C, Zhang J, Yang Y, Zhou F, Mater. Lett., 146, 47 (2015)
Qi S, Wang X, Luo J, Hu M, Zhao Q, Li Y, Zhang Z, IEEE International Vacuum Electronics Conference (IVEC), p.1, Beijing, China (2015).
Friedenstein H, Martin SL, Munday GL, Rep. Prog. Phys., 11, 298 (1946)
Weon BM, Je JH, Park GS, Koh NJ, Barratt DS, Saito T, J. Inf. Disp., 6, 35 (2005)
Newbury K, Lemery F, J. Opt. Soc. Am., 21, 276 (1931)
Park SK, Lee J, Jeon S, Kim RH, Jung J, Kim DJ, Kim DY, Lee KS, Mol. Cryst. Liq. Cryst., to be appeared 2019.
Yang HQ, Zhao H, Dong HX, Yang WY, Chen DC, Mater. Res. Bull., 44(5), 1148 (2009)
Cho YJ, Yang HC, Eun HC, Kim EH, Kim IT, J. Nucl. Sci. Technol., 43, 1280 (2006)
Chou SH, Voss J, Vojvodic A, Howe RT, Pedersen FA, J. Phys. Chem. C, 118, 11303 (2014)

[1] Lee DH, Choi DS, Jung YC, Kim SM, J. Korean Soc. Saf., 29, 34 (2014)

[2] Chang JS, Berezin AA, J. Electrostat, 51-52, 64 (2001)

[3] Inaba H, Ohmi T, Yoshida T, Okada T, J. Electrostat, 33, 15 (1994)

[4] Liu QL, Chen DR, J. Aerosol Sci., 76, 148 (2014)

[5] Herrmann IG, Wagener PS, The oxide coated cathode, p.1, Chapman and Hall Ltd., London, UK (1951).

[6] Langmuir I, Phys. Rev., 22, 357 (1923)

[7] Turner LW, Electronics Engineer's Reference Book, 4th ed., p.7, Newnes-Butterworth, London, England (1976).

[8] Herrmann IG, Wagener PS, The oxide coated cathode, p.218, Chapman and Hall Ltd., London, UK, (1951).

[9] Davis RF, BaO-CaO-Al2O3 Glass compositions, US Patent 3,852,079 (1974).

[10] Dong L, Wang J, Liu W, Li C, Zhang J, Yang Y, Zhou F, Mater. Lett., 146, 47 (2015)

[11] Qi S, Wang X, Luo J, Hu M, Zhao Q, Li Y, Zhang Z, IEEE International Vacuum Electronics Conference (IVEC), p.1, Beijing, China (2015).

[12] Friedenstein H, Martin SL, Munday GL, Rep. Prog. Phys., 11, 298 (1946)

[13] Weon BM, Je JH, Park GS, Koh NJ, Barratt DS, Saito T, J. Inf. Disp., 6, 35 (2005)

[14] Newbury K, Lemery F, J. Opt. Soc. Am., 21, 276 (1931)

[15] Park SK, Lee J, Jeon S, Kim RH, Jung J, Kim DJ, Kim DY, Lee KS, Mol. Cryst. Liq. Cryst., to be appeared 2019.

[16] Yang HQ, Zhao H, Dong HX, Yang WY, Chen DC, Mater. Res. Bull., 44(5), 1148 (2009)

[17] Cho YJ, Yang HC, Eun HC, Kim EH, Kim IT, J. Nucl. Sci. Technol., 43, 1280 (2006)

[18] Chou SH, Voss J, Vojvodic A, Howe RT, Pedersen FA, J. Phys. Chem. C, 118, 11303 (2014)