Despite extensive research on recently discovered layered ferromagnetic(FM)materials,their further development is hampered by the limited number of candidate materials with desired properties.As a much bigger family,l...Despite extensive research on recently discovered layered ferromagnetic(FM)materials,their further development is hampered by the limited number of candidate materials with desired properties.As a much bigger family,layered antiferromagnetic(AFM)materials represent excellent platforms to not only deepen our understanding of fundamental physics but also push forward high-performance spintronics applications.Here,by systematic first-principles calculations,we demonstrate pressure and carrier doping control of magnetic properties in layered AFM CoPS3,a representative of transition metal phosphorus trichalcogenides.In particular,pressure can drive isostructural Mott transition,in sharp contrast to other transition metal thiophosphates.Intriguingly,both pressure and carrier doping can realize the long-sought FM half-metallic states with 100%spin polarization percentage,which is good for improving the injection and detection efficiency of spin currents among others.Moreover,the Mott transition is accompanied by instantaneous spin-crossover(SCO)in CoPS3,and such cooperative SCO facilitates the implementation of fast-response reversible devices,such as data storage devices,optical displays and sensors.We further provide an in-depth analysis for the mechanisms of FM half-metallicity and SCO.Tunable magnetism in layered AFM materials opens vast opportunities for purposeful device design with various functionalities.展开更多
Ayers Rock is right in the centre ofAustralia.It’s nearly two thousand kilome-tres____1___Sydney.So we flew most of theway.It was rather cloudy___2____.But after weleft the mountains behind us,there washardly a cloud...Ayers Rock is right in the centre ofAustralia.It’s nearly two thousand kilome-tres____1___Sydney.So we flew most of theway.It was rather cloudy___2____.But after weleft the mountains behind us,there washardly a cloud in the sky.Most of the landbelow___3____sand,though Dad told me it wasgreener than I thought.“There are a lot ofsheep down there,”he said,“but____4__peo-ple!”展开更多
Nighttime enhancements in ionospheric electron density at mid- and low-latitudes are investigated by using the critical frequency of the F2-1ayer （foF2） data measured from ionosonde stations at Okinawa （26.3°N...Nighttime enhancements in ionospheric electron density at mid- and low-latitudes are investigated by using the critical frequency of the F2-1ayer （foF2） data measured from ionosonde stations at Okinawa （26.3°N, 127.8°E, Geomagnetic 15.3°N）, Yamagawa （31.2°N, 130.6°E, Geomagnetic 20.4°N）, Kokubunji （35.7°N, 139.5°E, Geomagnetic 25.5°N）, and Wakkanai （45.4°N, 141.7°E, Geomagnetic 35.4°N） in East Asia during several solar cycles. The results show that there are obvious seasonal and solar activity dependencies of the nighttime electron density enhancements. The enhancements are termed pre-midnight enhancement and post-midnight enhancement, according to the local time when the enhancement appeared. The former has a higher occurrence probability in summer months than in winter months. In contrast, the latter has a larger occurrence probability in winter months than in summer months. Moreover, the nighttime enhancements in electron density are more likely to occur at lower solar activity. These seasonal and solar activity variations of the nighttime enhancements in electron density can be explained in terms of the combined effects of downward plasma flux from the plasmasphere and the neutral winds.展开更多
基金the National Key Research and Development Program of China(2017YFB0701600)the National Natural Science Foundation of China(11974197 and 51920105002)+2 种基金Guangdong Innovative and Entrepre-neurial Research Team Program(2017ZT07C341)China Postdoctoral Science Foundation(2018M631458)the Bureau of Industry and Information Technology of Shenzhen for the 2017 Graphene Manufacturing Innovation Center Project(201901171523)。
文摘Despite extensive research on recently discovered layered ferromagnetic(FM)materials,their further development is hampered by the limited number of candidate materials with desired properties.As a much bigger family,layered antiferromagnetic(AFM)materials represent excellent platforms to not only deepen our understanding of fundamental physics but also push forward high-performance spintronics applications.Here,by systematic first-principles calculations,we demonstrate pressure and carrier doping control of magnetic properties in layered AFM CoPS3,a representative of transition metal phosphorus trichalcogenides.In particular,pressure can drive isostructural Mott transition,in sharp contrast to other transition metal thiophosphates.Intriguingly,both pressure and carrier doping can realize the long-sought FM half-metallic states with 100%spin polarization percentage,which is good for improving the injection and detection efficiency of spin currents among others.Moreover,the Mott transition is accompanied by instantaneous spin-crossover(SCO)in CoPS3,and such cooperative SCO facilitates the implementation of fast-response reversible devices,such as data storage devices,optical displays and sensors.We further provide an in-depth analysis for the mechanisms of FM half-metallicity and SCO.Tunable magnetism in layered AFM materials opens vast opportunities for purposeful device design with various functionalities.
文摘Ayers Rock is right in the centre ofAustralia.It’s nearly two thousand kilome-tres____1___Sydney.So we flew most of theway.It was rather cloudy___2____.But after weleft the mountains behind us,there washardly a cloud in the sky.Most of the landbelow___3____sand,though Dad told me it wasgreener than I thought.“There are a lot ofsheep down there,”he said,“but____4__peo-ple!”
基金supported by the projects of Chinese Academy of Sciences(Grant No.KZZD-EW-01-3)the National Basic Research Program of China(Grant No.2012CB825604)the National Natural Science Foundation of China(Grant Nos.41231065,41174137,41321003)
文摘Nighttime enhancements in ionospheric electron density at mid- and low-latitudes are investigated by using the critical frequency of the F2-1ayer （foF2） data measured from ionosonde stations at Okinawa （26.3°N, 127.8°E, Geomagnetic 15.3°N）, Yamagawa （31.2°N, 130.6°E, Geomagnetic 20.4°N）, Kokubunji （35.7°N, 139.5°E, Geomagnetic 25.5°N）, and Wakkanai （45.4°N, 141.7°E, Geomagnetic 35.4°N） in East Asia during several solar cycles. The results show that there are obvious seasonal and solar activity dependencies of the nighttime electron density enhancements. The enhancements are termed pre-midnight enhancement and post-midnight enhancement, according to the local time when the enhancement appeared. The former has a higher occurrence probability in summer months than in winter months. In contrast, the latter has a larger occurrence probability in winter months than in summer months. Moreover, the nighttime enhancements in electron density are more likely to occur at lower solar activity. These seasonal and solar activity variations of the nighttime enhancements in electron density can be explained in terms of the combined effects of downward plasma flux from the plasmasphere and the neutral winds.
