한 fm

Transcription

1 Journal of the Korean Magnetics Society, Volume 19, Number 4, August 2009 r g p p Áy Á 1 w w œw,, w w w w œw, w w w w, ( , , y ) w g (Corning glass)/ta(5 nm)/(permalloy, Conetic)/Ta(5 nm) w p w w. r (Permalloy; NiFe)d g p(conetic; NiFeCuMo)d w ƒ» w š» wš l sy» w ƒƒ w. ̃ 10~15 nm g p t w r 2 ù sy» 1/3 û, y 2~3 p ƒ. r p g p w v ù l w w ƒ y w. :, r, g p,,, y I.» q 1µG w» d w SQUID (Superconducting QUantum Interface Device)ù p (flux gate) š [1-3]. w l vƒ jš šƒ x y w ƒ ƒ š. y ƒ w š w 1µG w» d w» w v š x» r p ƒ w w [4-6].» ü q z ùkü» j, 100 mg š 10 5 y ƒ š. j ~ f y p ƒ [1, 7]. w» p w» w g p(conetic) d rl w r (Permalloy) d sy» y w.» p Ì 4- t w p w Ì» *Tel: (033) , [email protected] wš w. II. x Corning #7059 glass (ion beam deposition; IBD) l w w. w l Fig e k š œ(ultra-high Vacuum; UHV) l» œ ƒ Torr, w 3cm k q (grid) ev (Kaufmann source) [8,9]. v w š ƒ 0.2 mtorr, ³ w ƒ, (anode), ƒƒ 120 V, 30 V, 800 V, 6.0 ma. Fig. 1(a) 800 ev š- (Ar-ion) (beam) t š Ta, NiFe, Conetic k ƒ rl x»q. Ta, NiFe, Conetic ƒƒ nm/s, nm/s, nm/s. 3 e 3 mm Ì q x r g p kf 4N ƒ š, ƒƒ Ni 80 Fe 20, Ni 77 Fe 14 Cu 5 Mo 4. Ta, NiFe, Conetic EDS(Energy Dispersive Spectrum) w, š k 2% ü ew. AFM(Atomic 142

2 r g p p Áy Á Á 143 Force Microscopy) w Corning glass(7059)/ta(5 nm)/nife(5~10 nm) t e»ƒ 0.5~0.1 nm d, w» 350 Oe j» w w. Fig. 1(b) Ta/NiFe, NiFeCuMo/FeMn/Ta» y w p w» w NiFed NiFeCuMod w 1mm s ƒ 2 x j ƒw w» w ƒ αƒ 0 o, 90 o š w. 4 d w v w t w. r w w d yd Ta Ì 5nm yw, NiFed NiFeCuMod Ì p w š w» w 1nm 30 nm Ì ƒƒ w» wp w. Ì» (Magnetic Hysteresis; MH) š ƒƒ q lr(α-stepper) x d»(vibrating Sample Magnetometer; VSM), X- z»(x-ray Diffractometer; XRD) w w, 2 2cm 2 ü ³ w y w. w œ z w. (Coercivity; H EC ) y (Susceptibility; χ) 4-» wd l š» (anisotropy magnetoresistance; AMR) š ƒƒ w. III. x š w r j, Ni ƒ 78 % 100 % w ¾ y p sy B s 1.2 T 0.8 T w, w ρ 14 µωcm 6.0 µωcm w [10]. š w w 6.0 µωcm Ni 8.7 µωcm Fe w w ƒw» [10, 11]. g p j Ni 77 Fe 14 Cu 5 Mo 4 š w 5.0 µωcm Mo 1.5 µωcm Cu w ƒw w w 2 Fig. 1. (a) Schematic showing typical ion source, target, and substrate configuration inside ion beam deposition (IBD) system for fabricating the Corning glass(7059)/ta/permalloy(or conetic)/ta structure. (b) Schematic of the sample with 4-probe electrodes prepared by using shadow mask during deposition of multilayer. Here, arrows are noticed easy and hard axis, respectively. (c) Schematic configuration of conventional type with NiFe, NiFeCuMo single layer. Fig. 2. (a) Comparison of 4-probe surface resistance versus thickness for the permalloy and conetic films. (b) The y-axis scale is Log (natural) to analyze the coverage property for initial growth of the permalloy and conetic films. Two films show island growth mechanism by nonlinearity of resistance versus thickness curve.

3 144 w 4 w x z w t w ƒw. Fig. 2(a) r g p Ì 4- t w w. Fig. 2(a) Ì güp t w r t w 1.3~2.0 j ùkû. w d yd Ta z y z r g p t w ƒw. r g p y w Fig. 2(b) Ì t w š y, x w d d(layer-by-layer) x(island) [12]. w»q 100 o C w x d d» t e»ƒ skw [13]. Fig. 3 Fig. 1(b) w 1 mm s 4- w AMR z» wš š. j w w w. Fig. 3(a) glass/ta(5 nm)/conetic(15 nm)/ta(5 nm)» w ƒw d w AMR š Oe» 0Oe ù 0.25 Oe š, 5.0 Oe 0Oe ù +0.25Oe. AMR š w MH š w H EC 0.25 Oe. w»wz 19«4y, wr Fig. 3(b) Fig. 3(a) š w» ƒw d w glass/ta(5 nm)/conetic(15 nm)/ Ta(5 nm) AMR š. š AMR š w MH š l 0.3 Oe m y š d w MH š l sy» H HS x»» w [1]. š sy» y w w p. ƒ Fig. 3(b) H HS ƒ 1.5 Oe, (SQUID) d w» p emu, y M R 775 emu/cc.» d w 15 nm 8 mm 1 mm. y χ(= 10M R /H HS ) 5,167 ùkû [1, 14]. y 10 Egelhoff x l w [1]. w glass/ta(5 nm)/nife(15 nm)/ta(5 nm) w H EC, H HS, χ ƒƒ 1.25 Oe, 3.12 Oe, 2,467 ùkû. r g p w y p Table I w. Table I Ì y w g p r ƒƒ 1/5 š 2 j w p š. Fig. 4 w r g p Ì w š s y», y ùkü [14]. Egelhoffƒ tw x jù ex ̃ 50 nm 0.05 Oe Ì 20 nm w g p w t š [1]. w Ì w w IBD Ì w r 3nm r g p 1.8 Oe/1.2 Oe = 1.5 ù 9nm 1.5 Oe/0.5 Oe = 3.0, 15 nm 30 nm É 1.0 Oe/0.25 Oe = 4.0 w g p 1/3~1/4 š. š y š sy» r g p 4.0 Oe/3.0 Oe = 1.3 ù 9nm 3.3Oe/3.0Oe=1.6, 15 nm Fig. 3. Illustrations of MH loops and definitions of easy coercivity (H EC ) and hard saturation field (H HS ) from the (a) easy and (b) hard MR loops for the glass/ta(5 nm)/conetic(15 nm)/ta(5 nm) film. Here H HS is used to calculate the magnetic susceptibility (χ =10M R (remanent magnetization) H HS ). Here 10 is a compensated value of the extrapolated saturation field by Egelhoff s experimental data [1]. Table I. Typical easy coercivity, hard saturation field, remanent magnetization, and magnetic susceptibility of permalloy and conetic thin films with a thickness of 15 nm deposited on a Ta seed layer by ion beam deposition sputtering. Thin films Thickness H EC H HS M R χ NiFe 15 nm 1.25 Oe 3.12 Oe 770 emu/cc NiFeCuMo 15 nm 0.25 Oe 1.50 Oe 775 emu/cc 5,167

4 r g p p Áy Á Á 145 [1] w d r g p w 3~4 w š GMR-SV(giant magnetoresistance-spin valve)ù MTJ y w [15, 16]. w x mw y g p w IrMn FeMn Ru d Syntheticx SV MTJ w p w z twš w. IV. Fig. 4. Thickness dependence of the H EC, H HS, and of permalloy and conetic thin films for the glass/ta(5 nm)/nife, NiFeCuMo (t = 3~30 nm)/ta(5 nm) film prepared by ion beam deposition (IBD). 30 nm É 2.5Oe/1.2Oe=2.1 w g p 1/1.3~1/2.1 sy» š. w y r g p 0.7 ù Ì 9nm 0.3, 15 nm 30 nm É 0.25 w g p 3~30 nm ~ r 3 j y š. g p»l w (magnetic tunnel junction; MTJ) d w, w š d Al 2 O 3 d d g p y w j ƒwš y j j. w» (stray field) w ƒ e» w orange peel z w g pd Rud synthetic x w 1/10. Egelhoff tw w g (Corning glass)/ta(5 nm)/(permalloy, Conetic)/Ta(5 nm) w p w w. r (Permalloy)d g p (Conetic)d w ƒ» w š» wš l sy» w ƒƒ w. g p t w r t w 1.3~2.0 j ùkû. Ì t w š y r, x(island). g p r w 1/3~1/4 ƒ, y š sy» w w g p 3~30 nm ~ r j y š r p g p w v ù l w w ƒ y w ( w» ) w w» ( ). š x [1] W. F. Egelhoff Jr., R. D. McMichael, C. L. Dennis, M. D. Stiles, F. Johnson, A. J. Shapiro, B. B. Maranville, and C. J. Popwell, Thin Solid Films, 505, 90 (2006). [2] N. A. Stutzke, S. E. Russek, D. P. Pappas, and M. Tondra, J. Appl. Phys., 97, 10Q107 (2005). [3] C. W. Chen, Magnetism and Metallurgy of Soft Magnetic Materials, Dover, New York (1986). [4] M. Tondra, J. M. Daughton, C. Nordman, D. Wang, and J. Taylor, J. Appl. Phys., 87, 4679 (2000). [5] X. Liu, C. Ren, and G. Xiao. J. Appl. Phys., 92, 4722 (2002).

5 146 w»wz 19«4y, [6] M. E. McHenry, M. A. Willard, and D. E. Laughlin, Prog. Mater. Sci., 44, 291 (1999). [7] F. Pfeifer and C. Radeloff, J. Magn. Magn. Mater., 19, 190 (1980). [8] S. H. Park, K. S. Soh, G. Yoon, and S. S. Lee, J. Kor. Phys. Soc., 54, 2052 (2008). [9] S. S. Lee, B. Y. Kim, J. Y. Lee, D. G. Hwang, S. W. Kim, M. Y. Kim, J. Y. Hwang, and J. R. Rhee, J. Appl. Phys., 95, 7525 (2004). [10] H. E. Yang and H. S. Lee, Electromagnetic Materials, (Korean), Namdoo Books, pp. 42, 98 (2001). [11] C. Kittel, Introduction to Solid State Physics, Eighth Ed. John Wiley & Sons Inc, pp (2005). [12] D. Seong, S. S. Lee, and D. Youm, Solid State Commun., 76, 1341 (1990). [13] M. Ohring, Materials Science of Thin Films, 2nd Ed., Academic Press, pp (2002). [14] J. G. Choi, J. H. Choi, K. A. Lee, D. G. Hwang, J. R. Rhee, and S. S. Lee, Submitted to J. Kor. Phys. Soc. (2009). [15] D. W. Kim, J. H. Lee, M. J. Kim, and S. S. Lee, J. Magnetics, 14, 80 (2009). [16] W. H. Lee, D. G. Hwang, and S. S. Lee, J. Magnetics, 14, 18 (2009). Comparison of Soft Magnetic Properties of Permalloy and Conetic Thin Films Jong-Gu Choi 1, Do-Guwn Hwang 1,2, and Sang-Suk Lee 1,2 1 Dept. of Eastern-western Biomedical Engineering, Graduation, Sangji University, Wonju, Gangwondo , Korea 2 Dept. of Oriental Biomedical Engineering, Sangji University, Wonju, Gangwondo , Korea Jang-Roh Rhee Department of Physics, Sookmyung Women University, Seoul , Korea (Received 13 July 2009, Received in final form 21 August 2009, Accepted 21 August 2009) The soft magnetic property for the Corning glass/ta(5 nm)/[conetic, Permalloy)/Ta(3 nm) prepared by the ion beam deposition sputtering was investigated. The coercivity and saturation magnetic field of conetic (NiFeCuMo) and permalloy (NiFe) layer with easy and hard direction along to the applying magnetic field during deposition was compared with each other. The surface resistance of conetic film with a thickness of 10 nm was 2 times lower than one of permalloy film. The coercivity and the magnetic susceptibility of conetic film decreased and increased 3 times to one of permalloy film, respectively. These results suggest that a highly sensitive GMR- SV or MTJ using conetic film can be possible to develop the bio-device. Keywords : ion beam deposition (IBD) method, conetic thin film, permalloy thin film, coercivity, soft magnetic property, magnetic susceptibility