(a) Magnetization of films with and 0.9 nm under as a function of temperature. The insets show the decay with the applied magnetic field. (b) Magnetization vs field cycles at different temperatures.
(a) characteristics for thickness at different temperatures; Inset: logarithmic representation of the low-voltage Ohmic conductivity, , divided by as a function of the inverse temperature. (b) Current vs temperature (with ) for the same thickness.
Conductivity as a function of for thicknesses [fitted with the law of Sheng et al. (Ref. 28)].
(a) Field dependence of room-temperature MR at different thicknesses , where the IM law for 3D granular films (Ref. 31) is used for fitting MR vs ; (b) IM fits at different temperatures for (similar fits result for ).
Comparison between the mean magnetic moments of the granules (in unities of ) calculated from the fits to the MR (●) and from the magnetization curves (◼).
Critical behavior at the SPM-SFM transition vs nominal thickness of a granular layer: (a) maximum MR ratio , (b) MR field sensitivity at room temperature, and (c) field of maximum field sensitivity. The solid symbols stand for the previous data (Refs. 12 and 30) and the open symbols are for the present measurements. The vertical lines delimit the ranges of SPM, SFM, and FM phases at this temperature.
Maximum MR temperature dependence for both the thicknesses: and .
Sudden change from a noisy MR behavior to a low noise behavior at for .
Fitting parameters for the low-field magnetization curves as a function of temperature, Fig. 1(a).
Characteristic transport parameters for two nominal thickness values extracted from Fig. 3.
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