Evaluation of Adhesive Properties in Polymeric Thin Film by Ultrasonic Atomic Force Microscopy

ABSTRACTThe Ni80Fe20/Fe50Mn50,thin film system exhibits exchange bias behavior. Here a systematic study of the effect of atomic-scale thin film roughness on coercivity and exchange bias is presented. Cu (t) / Ta (100 Å) / Ni80Fe20 (100 Å) / Fe50Mno50 (200 Å) / Ta (200 Å) with variable thickness, t, of the Cu underlayer were DC sputtered on Si (100) substrates. The Cu underlayer defines the initial roughness that is transferred to the film material since the film grows conformal to the initial morphology. Atomic Force Microscopy and X-ray diffraction were used to study the morphology and texture of the films. Morphological characterization is then correlated with magnetometer measurements. Atomic Force Microscopy shows that the root mean square value of the film roughness exhibits a maximum of 2.5 Å at t = 2.4 Å. X-ray diffraction spectra show the films are polycrystalline with fcc (111) texture and the Fe50Mn50 (111) peak intensity decreases monotonically with increasing Cu thickness, t. Without a Cu underlayer, the values of the coercivity and loop shift are, Hc = 12 Oe and Hp = 56 Oe, respectively. Both the coercivity and loop shift change with Cu underlayer thickness. The coercivity reaches a maximum value of Hc= 36 Oe at t = 4 Å. The loop shift exhibits an initial increase with t, reaches a maximum value of HP = 107 Oe at t = 2.4 Å, followed by a decrease with greater Cu thickness. These results show that a tiny increase in the film roughness has a huge effect on the exchange bias magnitude.

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Scratching properties of nickel-iron thin film and silicon using atomic force microscopy

Journal of Applied Physics ◽

10.1063/1.3197313 ◽

2009 ◽

Vol 106 (4) ◽

pp. 044314 ◽

Cited By ~ 38

Author(s):

Ampere A. Tseng ◽

Jun-ichi Shirakashi ◽

Shinya Nishimura ◽

Kazuya Miyashita ◽

Andrea Notargiacomo

Keyword(s):

Thin Film ◽

Atomic Force Microscopy ◽

Nickel Iron ◽

Force Microscopy ◽

Atomic Force

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Evaluation of lubricant coverage on thin-film magnetic discs by atomic force microscopy

IEEE International Magnetics Conference ◽

10.1109/intmag.1999.837758 ◽

1999 ◽

Author(s):

W.B. Zhao ◽

D.G. Abel ◽

Tai Cheng ◽

J.L. Chao

Keyword(s):

Thin Film ◽

Atomic Force Microscopy ◽

Force Microscopy ◽

Atomic Force

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Atomic force microscopy of a ctpA mutant in Rhizobium leguminosarum reveals surface defects linking CtpA function to biofilm formation

Microbiology ◽

10.1099/mic.0.051045-0 ◽

2011 ◽

Vol 157 (11) ◽

pp. 3049-3058 ◽

Cited By ~ 21

Author(s):

Jun Dong ◽

Karla S. L. Signo ◽

Elizabeth M. Vanderlinde ◽

Christopher K. Yost ◽

Tanya E. S. Dahms

Keyword(s):

Atomic Force Microscopy ◽

Mutant Strain ◽

Biofilm Formation ◽

Rhizobium Leguminosarum ◽

Surface Defects ◽

Ion Concentration ◽

Adhesive Properties ◽

Surface Ultrastructure ◽

Force Microscopy ◽

Atomic Force

Atomic force microscopy was used to investigate the surface ultrastructure, adhesive properties and biofilm formation of Rhizobium leguminosarum and a ctpA mutant strain. The surface ultrastructure of wild-type R. leguminosarum consists of tightly packed surface subunits, whereas the ctpA mutant has much larger subunits with loose lateral packing. The ctpA mutant strain is not capable of developing fully mature biofilms, consistent with its altered surface ultrastructure, greater roughness and stronger adhesion to hydrophilic surfaces. For both strains, surface roughness and adhesive forces increased as a function of calcium ion concentration, and for each, biofilms were thicker at higher calcium concentrations.

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