Abstract
Experimental studies into the forced magnetostriction, magnetization, and temperature dependence of permeability in Ni2MnIn and Ni2MnSn ferromagnetic Heusler alloys were performed according to the spin fluctuation theory of itinerant ferromagnetism proposed by Takahashi. We investigated the magnetic field (H) dependence of magnetization (M) at the Curie temperature TC, and at T = 4.2 K, which concerns the ground state of the ferromagnetic state. The M-H result at TC was analyzed by means of the H versus M5 dependence. At 4.2 K, it was investigated by means of an Arrott plot (H/M vs. M2) according to Takahashi’s theory. As for Ni2MnIn and Ni2MnSn, the spin fluctuation parameters in k-space (momentum space, TA) and that in energy space (frequency space, T0) obtained at TC and 4.2 K were almost the same. The average values obtained at TC and 4.2 K were TA = 342 K, T0 = 276 K for Ni2MnIn and TA = 447 K, T0 = 279 K for Ni2MnSn, respectively. The forced magnetostriction at TC was also investigated. The forced linear magnetostriction (ΔL/L) and the forced volume magnetostriction (ΔV/V) were proportional to M4, which followed Takahashi’s theory. We compared the forced volume magnetostriction ΔV/V and mechanical parameter, bulk modulus K. ΔV/V is inversely proportional to K. We also discuss the spin polarization of Ni2MnIn and other magnetic Heusler alloys. The pC/pS of Ni2MnIn was 0.860. This is comparable with that of Co2MnGa, which is a famous half-metallic alloy.
Highlights
Spin fluctuation theories have been proposed to explain the physical properties and the principles of itinerant electron systems [1,2,3,4,5,6,7]
We considered the magnetostriction and magneto-volume effects of these alloys
We describe the of forced magnetostrictions for Ni2MnIn and
Summary
Spin fluctuation theories have been proposed to explain the physical properties and the principles of itinerant electron systems [1,2,3,4,5,6,7]. Materials 2020, 13, 2017 magnetization (M–H), the effect of non-linear mode–mode couplings is associated with the second lowest expansion of free energy in regard to magnetization M In this theory, the spin fluctuations of the higher order coefficient are neglected. TA is expressed in the form of TA = Aq2B , where q2B indicates the effective zone boundary wave vector, and A indicates the non-dimensional parameter, as shown in Equation (3.6) in reference [2] Another parameter, T0 , is a spectral distribution ΓqB in the frequency space, which was defined by ΓqB = 2πkB T0. Where kB indicates the Boltzmann factor, and ζ indicates the slope of the Arrott plot (M2 versus H/M) These equations use units of kOe and emu/g for the magnetic fields H and magnetization M, respectively ∆V/V as shown by Equation (4), and evaluated the correlation between the magnetization and ∆V/V
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
