Alloys of Fe49Co49V2 (Hiperco Alloy 50) (Hiperco is a registered trademark of CRS Holdings, Inc.), both annealed and thermally aged, were studied using anomalous synchrotron x-ray and neutron powder diffraction. Rietveld and diffraction profile analysis indicated both an increase in the structural order parameter and a small lattice expansion (∼0.0004 Å) after aging at 450 °C for 200 h. In addition, a cubic minority phase (<0.3%) was identified in the ‘‘annealed’’ sample, which increased noticeably (0.3%→0.8%) as a result of aging. The presence of antiphase domain boundaries in the alloys was also revealed. These results directly correlate with the observed changes in the magnetization behavior and challenge the notion that a ‘‘fully’’ ordered Fe–Co alloy demonstrates optimum soft magnetic properties.

The structural characteristics of GaN films grown on sapphire substrates by molecular beam epitaxy have been investigated using high-resolution synchrotron x-ray diffraction and electron microscopy. We find remarkable correspondence between the in-plane structural order (coherence length and mosaic spread) and the electrical and optical properties. Contrary to common belief, our observations show unequivocally that the out-of-plane structural features, which are considerably better developed than the in-plane counterparts, cannot be used for determining the material quality with respect to their optical and electrical activity. In particular, the (00l) mosaic spread is not a good indicator of film quality.

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Amorphous (Fe40Ni40B19Cu1)100−x Nb x (x = 1, 3, 5, 7) ribbons are prepared by using the melt-spinning method. We find that the glass forming ability (GFA) of the as-melt spun ribbons is significantly improved by adding Nb element. In addition, the thermal stability evaluated in steps of Δ T = T x 2 − T x 1 effectively increases from 16 K to 75 K with Nb content increasing. The as-melt spun (Fe40Ni40B19Cu1)97Nb3 ribbon exhibits a lowest coercivity of 2 A/m and relatively large saturation magnetization of 103.7 A · m 2 / kg and thus it can be further treated by being annealed at 809 K. The crystallization behavior is confirmed to be determined by two individual crystallization processes corresponding to the precipitation of (Fe,Ni)23B6 phase and γ-(Fe,Ni) phase. With increasing annealing time, the single (Fe,Ni)23B6 phase can be transformed into a mixture of (Fe,Ni)23B6 and γ-(Fe,Ni) phase, and the grain size of γ-(Fe, Ni) phase increases from 5 nm to 80 nm while the grain size of (Fe,Ni)23B6 remains almost unchanged. Finally, we find that the grain growth in each of (Fe,Ni)23B6 and γ-(Fe, Ni) deteriorates the overall magnetic properties.

We established the vibration governing equation for a magnetoelastic (ME) biosensor with target loading in liquid. Based on the equation, a numerical simulation approach was used to determine the effect of the target loading position and viscous damping coefficient on the node (“blind points”) and mass sensitivity (Sm) of an ME biosensor under different order resonances. The results indicate that viscous damping force causes the specific nodes shift but does not affect the overall variation trend of Sm as the change of target loading position and the effect on Sm gradually reduces when the target approaches to the node. In addition, Sm decreases with the increase of viscous damping coefficient but the tendency becomes weak at high-order resonance. Moreover, the effect of target loading position on Sm decreases with the increase of viscous damping coefficient. Finally, the results provide certain guidance on improving the mass sensitivity of an ME biosensor in liquid by controlling the target loading position.

(Fe40Ni40B19Cu1)97Nb3 magnetic amorphous alloys have been prepared by a melt-spun method, and their crystallization behavior and kinetics have been investigated. The results showed that under non-isothermal conditions, the growth process is easier than the nucleation process for both precipitated phases ((Fe,Ni)23B6 and γ­(Fe,Ni)), and the activation energy (E a 2 = 427.03 kJ mol–1) for γ­(Fe,Ni) phase is higher than that of (E a 1 = 275.11 kJ mol–1) for the (Fe,Ni)23B6 phase. Under isothermal conditions, the energy released during the entire crystallization process is independent of annealing temperature, and the crystallization parameters fit with the Kolmogorov–Johnson–Mehl–Avrami (KJMA) model well. The nucleation activation energy (E n ) and growth activation energy (E g ) are 429.2 and 417.2 kJ/mol, respectively. Based on the values of the Avrami exponent n, the transformation process can be divided into three different stages: Stage I, n ≈ 2.5; Stage II, 2.5 ≤ n ≤ 3; Stage III, n > 3. The whole crystallization process from interface-controlled one-dimensional growth converted into interface-controlled three-dimensional growth.