Early stage phase segregation of block copolymers (BCPs) critically impacts the material’s final structural properties, and understanding the kinetics of these processes is essential to intentional design of systems for practical applications. Using sub-millisecond lateral gradient laser spike annealing and microbeam grazing incidence small-angle X-ray scattering, the ordering and disordering kinetics of cylinder forming poly(styrene-b-methyl methacrylate) (PS-b-PMMA) were determined for peak annealing temperatures up to 550 °C for dwells (anneal durations) ranging from 250 μs to 10 ms. These temperatures, far in excess of the normal thermal decomposition limit, are enabled by the short time scales of laser annealing. From initially microphase-segregated films, disordering was observed near the equilibrium order–disorder transition temperature (TODT) for dwell times above 10 ms but was kinetically delayed by diffusion for shorter time scales, resulting in suppression of observed disordering by over 70 °C. The onset of ordering from initially disordered films was also kinetically limited for short dwells. For anneals with peak temperatures well above TODT, the block copolymer fully disorders and quenches to a history-independent final state determined by the quench rate. This kinetic behavior can be represented on an effective Tg and TODT phase map as a function of the heating time scale. These results then potentially enable BCP processing to retain or intentionally modify the initial state while accelerating kinetics for other chemical or structural alignment processes
The effect of covalent element addition on the magnetic and magnetocaloric properties of ferrimagnetic Gd60Co20Fe20 amorphous alloy was studied. Particularly, the co-doping of B and Si promoted the magnetocaloric performance (with a larger magnetic entropy change |ΔSM| at higher working temperature) of the initial Gd60Co20Fe20 amorphous alloy. This is possibly ascribed to the modified magnetic transition behavior. Additionally, the broadened magnetocaloric effect with |ΔSM| of 2.25 J kg−1 K−1 at 222.5 K under a magnetic field change of 0–2 T and high relative cooling power of 396.0 J kg−1 were obtained for (Gd0.6Co0.2Fe0.2)95B2Si3. These properties reveal that the material could be a good candidate as a magnetic refrigerant suitable for active magnetic refrigerators.
Applying the appropriate ratio of hydrochloric acid and nitric acid mixed solvents, the aluminum and aluminum alloy products were completely digested, and then the digestion solution was diluted with water to a constant volume, and directly using inductively coupled plasma atomic emission spectrometry (ICP-OES) to test Ga and the content of which is from 0.005 to 1.0%. This paper has examined the effect of high aluminum matrix and coexisting elements on the interference of testing micro gallium, and by optimizing the parameters of the instrument detection such as gallium analytical line, detection integration region and synchronization background correction position, etc., effectively eliminated the spectral interferences of coexistence impurity elements. The method have optimized instrument working conditions of the plasma emission spectrometer, and taken matrix matching and synchronization background correction combination of technical measures to eliminate the matrix effect of aluminum products. The method is simple and practical, easy to operate, and avoid the complicated chemical separation and enrichment procedures, with fewer steps, shorter inspection cycle, wide detection range, high precision and accuracy. The results of the method for the determination of the gallium in the aluminum and aluminum products show that: the detection limit of 0.0002%, the background equivalent concentration of 0.00004% and the RSD is less than 2%, the recoveries is from 96.0% to 104.0%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.