Electric and Magnetic Signatures of Structural and Chemical Ordering of Heusler Alloy Films

Abstract

We present results of in situ temperature measurements of resistivity for some amorphous or partially crystalline Heusler alloy films: Co 2 CrAl, Co 2 MnGa and off-stoichiometric Ni 2 Mn 1+x Sn x , Ni 2 Mn 1−x Ga x that are known to exhibit half-metallic properties and martensitic transformations, respectively. From ρ vs. T characteristics we distinguish various stages of chemical and structural ordering in the films. They appear to be quite distinct in both systems investigated. The resistivity results are compared with magnetic characteristics for Co 2 MnGa with a high Curie temperature.

Enhancing the Squareness and Bi-phase Magnetic Switching of Co2FeSi Microwires for Sensing Application

“…It is known, that a split in the brag diffraction patterns lead to a small distortion of the crystalline structure [45]. The absence of a (400) peak around 85 ⁰ , which is expected to be present in the A2 structure, increases the possibility that the crystallites are too fine to be detected by X-rays, as reported elsewhere [46]. In addition, the absence of some peaks can be caused by a similar scattering factor of the constituent elements (Co, Fe, and Si) [47].…”

“…Figure 3 shows the magnetic hysteresis loops of Co2FeSi glass-coated microwires with different ρ-ratios, obtained at room temperature with an applied magnetic field parallel to the microwire axis. All samples exhibit typical ferromagnetic behaviour, due to the high Curie point of Co2FeSi alloy greater than 1100 K [46]. The sample with low ρ -ratio exhibits soft magnetic properties with coercivity, Hc, around 14 Oe and non-square hysteresis loop shape (Figure 3a).…”