Magnetization–structure–composition phase diagram mapping in Co-Fe-Ni alloys using diffusion multiples and scanning Hall probe microscopy

Abstract

Transition metal alloys are essential for magnetic recording, memory, and new materials-by-design applications. Saturation magnetization in these alloys have previously been measured by conventional techniques, for a limited number of samples with discrete compositions, a laborious and time-consuming effort. Here, we propose a method to construct complete saturation magnetization diagrams for Co–Fe–Ni alloys using scanning Hall probe microscopy (SHPM). A composition gradient was created by the diffusion multiple technique, generating a full combinatorial materials library with an identical thermal history. The composition and crystallographic phases of the alloys were identified by integrated energy dispersive X-ray spectroscopy and electron backscatter diffraction. “Pixel-by-pixel” perpendicular components of the magnetic field were converted into maps of saturation magnetization using the inversion matrix technique. The saturation magnetization dependence for the binary alloys was consistent with the Slater-Pauling behavior. By using a significantly denser data point distribution than previously available, the maximum of the Slater-Pauling curve for the Co–Fe alloys was identified at ~ 32 at% of Co. By mapping the entire ternary diagram of Co–Fe–Ni alloys recorded in a single experiment, we have demonstrated that SHPM—in concert with the combinatorial approach—is a powerful high-throughput characterization tool, providing an effective metrology platform to advance the search for new magnetic materials.

Selective Reduction of Multivariate Metal–Organic Frameworks for Advanced Electrocatalytic Cathodes in High Areal Capacity and Long-Life Lithium–Sulfur Batteries

“…The synthetic process of CoNiFe 3 O 4 /PC was targeted with an atom ratio of Co/Ni (Fe) ∼ 2:1 to obtain CoNi alloy with the highest fcc-phase strength based on the Co–Ni–Fe phase diagram. , The Co–Ni phase diagram indicates that the hardness of CoNi alloys increases as the cobalt content increases. , Thus, increasing the cobalt content in the crystal is beneficial for the stability of the structure. ICP-OES and EDS were used to analyze the proportion of Co, Ni, and Fe and the average metal weight percent of bare and carbonized CoNiFe-MOF-74 (Table S1).…”

Carbon–Ni6Co3Fe1 alloy hybrid foil for electromagnetic wave interference shielding in X-band and extremely low frequencies

“…S7, ESI †). 38 NiCoFe also showed much lower coercivity (16.6 Oe) compared to Ni (52.2 Oe) and Co (117.8 Oe) (Fig. 4e), highlighting that the NiCoFe film can be easily magnetized to serve as a shield against ELF magnetic fields.…”

Cutting Edge High‐Throughput Synthesis and Characterization Techniques in Combinatorial Materials Science

“…[144][145][146][147] Shamsutdinov et al used it to measure the magnetization of the Co-Fe-Ni composition gradient at room temperature in ≈5 T external magnetic field along the normal direction, with 100 μA Hall probe current and ≈5 × 10 4 Ω/Gauss Hall coefficient with electronics gain of 10 3 . [144] The Hall bar active area is [150] Copyright 2021, Wiley-VCH. c) Schematic diagram of automated electrolyte experiment.…”

“…The SHPM (Figure 21f,g) can be used to measure the magnetic property of materials applied in magnetic recording or rare earth-free hard magnets, with features like noninvasive, sub-μm spatial resolution and quantitative detection of large magnetic fields. [144][145][146][147] Shamsutdinov et al used it to measure the magnetization of the Co-Fe-Ni composition gradient at room temperature in ≈5 T external magnetic field along the normal direction, with 100 μA Hall probe current and ≈5 × 10 4 Ω/Gauss Hall coefficient with electronics gain of 10 3 . [144] The Hall bar active area is [150] Copyright 2021, Wiley-VCH.…”

“…i) Saturation magnetization diagram of the Co‐Fe‐Ni samples. [ 144 ] Copyright 2022, Springer Nature.…”