KAJIAN MAGNETORESISTANSI PADA BIOMATERIAL DENGAN SENSOR LAPISAN TIPIS Co/Cu MULTILAYER GIANT MAGNETORESISTANCE (GMR) BERBASIS NANOPARTIKEL Fe3O4; STUDY OF MAGNETORESISTANCE ON BIOMATERIAL USING Fe3O4 NANOPARTICLES-BASED Co/Cu THIN FILM MULTILAYERS GIANT MAGNETORESISTANCE (GMR) SENSOR

FERAWATI ARTAULI HASIBUAN, Edi Suharyadi

2015 | Disertasi | FMIPA

A study of magnetoresistance has been done on magnetite nanoparticle (Fe3O4) encapsulated with polyethylene glycole (PEG) and biomaterials using thin film sensor based on giant magnetoresistance (GMR). The thin film used is Si/Cr(5nm)/[Co(1.5nm)/Cu(x)]20/Cr(5nm) multilayer (x = 0.8; 0.9; dan 1.0 nm). GMR phenomenon that appears influenced by the thin film thickness variation and nanoparticle coatings which is functionalized with PEG and addition of biomolecule that effected the mobility of magnetic moment. Resistances on the Cu layer with thickness of 0.8; 0.9 nm; and 1.0 nm when H = 0 are 3.70±0.06; 3.51±0.06; and 2.74±0.05 ?, respectively, and when H = 588.82 G are 3.52±0.06; 3.26±0.08; and 2.40±0.05 ?, respectively. The value of MR when a thin film coated by Fe3O4 nanoparticles, Fe3O4 functionalized with PEG, and Fe3O4 encapsulated with PEG and addition of biomolecule undergo different changes. The value of resistance after being coated the nanoparticles Fe3O4 with a layer thickness variation Cu when H = 0, 59.21±4.04; 12.36±0.06; and 42.15±0.58? and when H = 588.82 G, 19.40±1.60; 11.71±0.04; and 27.53±0.46?, respectively. MR ratio when coated nanoparticles Fe3O4 functionalized with PEG on the thickness of each layer is 205.1% Cu; 5.6%; and 53%. MR ratio when coated nanoparticles magnetite functionalized with PEG and the addition of biomolecules on the thickness of each layer Cu is 5.51%; 25.7%; and 10.03%. The change of MR value in the thin film multilayer before and after being coated indicate that the thin film multilayer can be applied as a magnetic field sensor and it is potential as a biosensor.

Kata Kunci : Giant magnetoresistance (GMR); thin film multilayers, nanoparticles Fe3O4; polyethylene glycole (PEG); biomolecule