Obviously planar anisotropy due to‘TD split’orthotropic texture(TD indicates Transverse direction)always exist in the Rare-earth(RE)or Ca containing Mg alloy sheets,which is likely caused by the lowreduction rolling...Obviously planar anisotropy due to‘TD split’orthotropic texture(TD indicates Transverse direction)always exist in the Rare-earth(RE)or Ca containing Mg alloy sheets,which is likely caused by the lowreduction rolling(and annealing)as revealed in our previous research.In this work,the as-cast billets of a ZWK100 alloy were subjected to final-pass heavy reduction rolling(FHRR)at 500°C with different reductions(30%-70%)after rough rolling,aiming to investigate the reduction effect on the microstructure and texture formation.The results show that FHRR with higher reductions above 50%is in favor of shear banding formation but has little effect on the as-deformed texture components,and the excellent formability with single-pass reduction up to 70%is mainly ascribed to the activation of prismatic slip.FHRR with reduction above 50%and annealing can generate uniform grain structures of~10μm and symmetrical‘oblique-line split’texture in(0001)pole figures,with basal poles tilting by about 50°from ND(Normal direction)towards some oblique-line of TD and RD(Rolling direction)as well as uniform distribution of counter lines as an annular shape,resulting in excellent elongation to failure of~50%and ultra-low planar anisotropyΔr_of~0.1 and high stretch formability(Erichsen value:8.1).The formation‘oblique-line split’texture in(0001)pole figures is mainly correlated with the preferred growth tendency of grains with■//RD,which was suggested to relate to the high mobility of some special boundaries such as 40°-45°■.The influences of starting textures on the mechanical properties,planar anisotropy and related deformation modes,as well as their correlations with the stretch formability were comparatively investigated with the‘TD split’orthotropic texture as a counterpoint.展开更多
Two-dimensional(2D)ferromagnets with out-of-plane(OOP)magnetic anisotropy are potential candidates for realizing the next-generation memory devices with ultra-low power consumption and high storage density.However,a s...Two-dimensional(2D)ferromagnets with out-of-plane(OOP)magnetic anisotropy are potential candidates for realizing the next-generation memory devices with ultra-low power consumption and high storage density.However,a scalable approach to synthesize 2D magnets with OOP anisotropy directly on the complimentary metal-oxide semiconductor(CMOS)compatible substrates has not yet been mainly explored,which hinders the practical application of 2D magnets.This work demonstrates a cascaded space confined chemical vapor deposition(CS-CVD)technique to synthesize 2D FexGeTe_(2) ferromagnets.The weight fraction of iron(Fe)in the precursor controls the phase purity of the as-grown FexGeTe2.As a result,high-quality Fe_(3)GeTe_(2) and Fe_(5)GeTe_(2) flakes have been grown selectively using the CS-CVD technique.Curie temperature(Tc)of the as-grown FexGeTe2 can be up to-280 K,nearly room temperature.The thickness and temperature-dependent magnetic studies on the Fe_(5)GeTe_(2) reveal a 2D Ising to 3D XY behavior.Also,Terahertz spectroscopy experiments on Fe_(5)GeTe_(2) display the highest conductivity among other FexGeTe_(2) 2D magnets.The results of this work indicate a scalable pathway for the direct growth and integration of 2D ternary magnets on CMOS-based substrates to develop spintronic memory devices.展开更多
基金financially supported by Basic and Applied Basic Research Fund of Guangdong Province of China(No.2019A1515110573)National Natural Science Foundation of China(No.51901047)+2 种基金Special Innovation Projects of Universities in Guangdong Province(2018KTSCX240)Key Project of Department of Education of Guangdong Province(No.2016GCZX008)Project of Engineering Research Center of Foshan(No.20172010018)。
文摘Obviously planar anisotropy due to‘TD split’orthotropic texture(TD indicates Transverse direction)always exist in the Rare-earth(RE)or Ca containing Mg alloy sheets,which is likely caused by the lowreduction rolling(and annealing)as revealed in our previous research.In this work,the as-cast billets of a ZWK100 alloy were subjected to final-pass heavy reduction rolling(FHRR)at 500°C with different reductions(30%-70%)after rough rolling,aiming to investigate the reduction effect on the microstructure and texture formation.The results show that FHRR with higher reductions above 50%is in favor of shear banding formation but has little effect on the as-deformed texture components,and the excellent formability with single-pass reduction up to 70%is mainly ascribed to the activation of prismatic slip.FHRR with reduction above 50%and annealing can generate uniform grain structures of~10μm and symmetrical‘oblique-line split’texture in(0001)pole figures,with basal poles tilting by about 50°from ND(Normal direction)towards some oblique-line of TD and RD(Rolling direction)as well as uniform distribution of counter lines as an annular shape,resulting in excellent elongation to failure of~50%and ultra-low planar anisotropyΔr_of~0.1 and high stretch formability(Erichsen value:8.1).The formation‘oblique-line split’texture in(0001)pole figures is mainly correlated with the preferred growth tendency of grains with■//RD,which was suggested to relate to the high mobility of some special boundaries such as 40°-45°■.The influences of starting textures on the mechanical properties,planar anisotropy and related deformation modes,as well as their correlations with the stretch formability were comparatively investigated with the‘TD split’orthotropic texture as a counterpoint.
基金supported from National Research Foundation Singapore programme NRF-CRP22-2019-0007,NRF-CRP22-2019-0004 and NRF-CRP21-2018-0007supported by the Ministry of Education,Singapore,under its AcRF Tier 3 Programme‘Geometrical Quantum Materials’(MOE2018-T3-1-002),AcRF Tier 2(MOE2019-T2-2-105)and AcRF Tier 1 RG4/17 and RG7/18We also thank the funding support from National Research foundation(NRF-CRP22-2019-0004).
文摘Two-dimensional(2D)ferromagnets with out-of-plane(OOP)magnetic anisotropy are potential candidates for realizing the next-generation memory devices with ultra-low power consumption and high storage density.However,a scalable approach to synthesize 2D magnets with OOP anisotropy directly on the complimentary metal-oxide semiconductor(CMOS)compatible substrates has not yet been mainly explored,which hinders the practical application of 2D magnets.This work demonstrates a cascaded space confined chemical vapor deposition(CS-CVD)technique to synthesize 2D FexGeTe_(2) ferromagnets.The weight fraction of iron(Fe)in the precursor controls the phase purity of the as-grown FexGeTe2.As a result,high-quality Fe_(3)GeTe_(2) and Fe_(5)GeTe_(2) flakes have been grown selectively using the CS-CVD technique.Curie temperature(Tc)of the as-grown FexGeTe2 can be up to-280 K,nearly room temperature.The thickness and temperature-dependent magnetic studies on the Fe_(5)GeTe_(2) reveal a 2D Ising to 3D XY behavior.Also,Terahertz spectroscopy experiments on Fe_(5)GeTe_(2) display the highest conductivity among other FexGeTe_(2) 2D magnets.The results of this work indicate a scalable pathway for the direct growth and integration of 2D ternary magnets on CMOS-based substrates to develop spintronic memory devices.