scholarly journals Analisa Magnetoresistance Berbasis Lapisan Tipis Giant Magnetoresistance (GMR) Pada Nanopartikel Cobalt Ferrite (CoFe2O4) Dilapisi Polyethylen Glicol (PEG)

2017 ◽  
Vol 20 (1) ◽  
pp. 6
Author(s):  
Novi Susanti ◽  
Edi Suharyadi

Telah dilakukan pengukuran magnetoresistance pada lapisan tipis spin valve GMR yang memiliki struktur CoFeB/Cu/CoFe/MnIr dengan memvariasikan ketebalan lapisan barrier Cu (2,2 dan 2,8 nm) dan free layer CoFeB (7 dan 10 nm) menggunakan System Four Point Probe Method (SFPPM) pada medan eksternal 0 600 gauss. Dihasilkan perubahan range resistansi (69,29-71,74) Ω untuk Cu 2,2 nm dan (38,5-40,47) Ω untuk ketebalan Cu 2,8 nm. Pada variasi ketebalan CoFeB dihasilkan perubahan range resistansi untuk ketebalan 7 nm dan 10 nm masing masing adalah (38,74-41,11) Ω dan (69,29-71,74) Ω. Selanjutnya lapisan tipis digunakan sebagai sensor magnetik untuk mendeteksi kehadiran nanopartikel CoFe2O4, CoFe2O4 yang dimodifikasi PEG dan CoFe2O4 termodifikasi PEG yang telah mengikat biomolekul formalin. Terjadi pergeseran nilai resistansi ketika lapisan tipis dilapisi nanopartikel magnetik tersebut. Hal ini menunjukkan bahwa lapisan tipis GMR mampu mendeteksi prilaku spin pada nanopartikel magnetik CoFe2O4. 

2006 ◽  
Vol 6 (11) ◽  
pp. 3483-3486
Author(s):  
Chunghee Nam ◽  
Youngman Jang ◽  
Ki-Su Lee ◽  
Jungjin Shim ◽  
B. K. Cho

We have studied the influence of the insertion of a nano-oxide layer (NOL) into a magnetic GMR spin-valve. It was found that the spin-valve with NOL has a higher GMR ratio than that of the normal spin-valve without NOL. Naturally formed NOL without vacuum break shows a uniform layer, which effectively suppresses the current shunt, resulting in the reduction of the sheet resistance of GMR. The NOL spin-valve also shows a lower interlayer coupling (Hin) than that of the optimal normal spin-valve, which is consistent with AFM measurement showing lower roughness of NOL formed CoFe surface. Based on the advantage of NOL, we succeeded in lowering Hin while maintaining GMR ratio by insertion of NOL inside the CoFe free layer, where the free layer consists of CoFe/NOL/CoFe/NOL/Capping layer.


2000 ◽  
Vol 87 (9) ◽  
pp. 5377-5382 ◽  
Author(s):  
Satoru Araki ◽  
Masashi Sano ◽  
Shuxiang Li ◽  
Yoshihiro Tsuchiya ◽  
Olivier Redon ◽  
...  

2005 ◽  
Vol 97 (10) ◽  
pp. 10C507 ◽  
Author(s):  
Ken-ichi Aoshima ◽  
Nobuhiko Funabashi ◽  
Kenji Machida ◽  
Yasuyoshi Miyamoto ◽  
Kiyoshi Kuga

2012 ◽  
Vol 113 (4) ◽  
pp. 341-348 ◽  
Author(s):  
V. V. Ustinov ◽  
M. A. Milyaev ◽  
L. I. Naumova ◽  
V. V. Proglyado ◽  
N. S. Bannikova ◽  
...  
Keyword(s):  

2012 ◽  
Vol 111 (7) ◽  
pp. 07E504 ◽  
Author(s):  
Seungha Yoon ◽  
Youngman Jang ◽  
Chunghee Nam ◽  
Seungkyo Lee ◽  
Joonhyun Kwon ◽  
...  

1995 ◽  
Vol 384 ◽  
Author(s):  
J. B. Restorff ◽  
M. Wun-Fogle ◽  
S. F. Cheng ◽  
K. B. Hathaway

ABSTRACTWe have observed time dependent magnetic switching in spin-valve sandwich structures of Cu/Co/Cu/Fe films grown on silicon and Kapton substrates and Permalloy/Co/Cu/Co films grown on NiO or NiO/CoO coated Si substrates. The giant magnetoresistance (MR) values ranged from 1 to 3 percent at room temperature. The films were grown by DC magnetron sputter deposition. Measurements were made on the time required for the MR to stabilize to about 1 part in 104 after the applied field was incremented. This time depends almost linearly on the amplitude of the timedependent MR change with a slope (time / ΔMR) of 20 000 to 30 000 s. Some samples took as long as 70 s to stabilize. The time dependent effects may be important for devices operating in these regions of the magnetoresistance curve. In addition, measurements were made on the time history of the MR value for a period of 75 s following a step change in the field from saturation. We observed that the time dependent behavior of the MR values of both experiments produced an excellent fit to a function of the form ΔMR(t) = α + β;ln(t) where ɑ and β are constants. This time dependence was consistent with the behavior of the magnetic aftereffect.


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