查看更多>>摘要：Exploring dimensionality effects on cuprates is important for understanding the nature of high-temperature superconductivity.By atomically layer-by-layer growth with oxide molecular beam epitaxy,we demonstrate that La2-xSrxCuO4(x=0.15)thin films remain superconducting down to 2 unit cells of thickness but quickly reach the maximum superconducting transition temperature at and above 4 unit cells.By fitting the critical magnetic field(μoHc2),we show that the anisotropy of the film's superconductivity increases with decreasing film thickness,indicating that the superconductivity of the film gradually evolves from weak three-to two-dimensional character.These results are helpful to gain more insight into the nature of high-temperature superconductivity with dimensionality.
查看更多>>摘要：Proximity effects between superconductors and ferromagnets(SC/FM)hold paramount importance in com-prehending the spin competition transpiring at their interfaces.This competition arises from the interplay between Cooper pairs and ferromagnetic exchange interactions.The proximity effects between transition metal nitrides(TMNs)are scarcely investigated due to the formidable challenges of fabricating high-quality SC/FM interfaces.We fabricated heterostructures comprising SC titanium nitride(TiN)and FM iron nitride(Fe3N)with precise chemical compositions and atomically well-defined interfaces.The magnetoresistance of Fe3N/TiN heterostruc-tures shows a distinct magnetic anisotropy and strongly depends on the external perturbations.Moreover,the superconducting transition temperature Tc and critical field of TiN experience notable suppression when prox-imity to Fe3N.We observe the intriguing competition of interfacial spin orientations near TC(～1.25 K).These findings not only add a new materials system for investigating the interplay between superconductor and fer-romagnets,but also potentially provide a building block for future research endeavors and applications in the realms of superconducting spintronic devices.
查看更多>>摘要：Two-dimensional(2D)magnetic materials have been demonstrated to have excellent chemical,optical,elec-trical,and magnetic properties,particularly in the development of multifunctional electronic and spin electronic devices,showcasing tremendous potential.Therefore,corresponding synthesis techniques for 2D magnetic ma-terials that offer high quality,high yield,low cost,time-saving,and simplicity are highly desired.This review provides a comprehensive overview of recent research advances in preparation of magnetic 2D materials,with a particular focus on the preparation methods employed.Moreover,the characteristics and applications of these magnetic materials are also discussed.Finally,the challenges and prospects of synthesis methods for magnetic 2D materials are briefly addressed.This review serves as a guiding reference for the controlled synthesis of 2D magnetic materials.
查看更多>>摘要：The exploration and research of low-cost,environmentally friendly,and sustainable organic semiconductor materials are of immense significance in various fields,including electronics,optoelectronics,and energy con-version.Unfortunately,these semiconductors have almost poor charge transport properties,which range from～10-4 cm2·V-1·s-1 to～10-2 cm2·V-1·s-1.Vat orange 3,as one of these organic semiconductors,has great potential due to its highly conjugated structure.We obtain high-quality multilayered Vat orange 3 crystals with two-dimensional(2D)growth on h-BN surfaces with thickness of 10-100 nm using physical vapor transport.Ra-man's results confirm the stability of the chemical structure of Vat orange 3 during growth.Furthermore,by leveraging the structural advantages of 2D materials,an organic field-effect transistor with a 2D vdW vertical het-erostructure is further realized with h-BN encapsulation and multilayered graphene contact electrodes,resulting in an excellent transistor performance with On/Off ratio of 104 and high field-effect mobility of 0.14cm2·V-1·s-1.Our results show the great potential of Vat orange 3 with 2D structures in future nano-electronic applications.Furthermore,we showcase an approach that integrates organic semiconductors with 2D materials,aiming to offer new insights into the study of organic semiconductors.
查看更多>>摘要：There have been several studies on sulfur depletion in dense cores like TMC-1(Taurus Molecular Cloud 1),employing updated reaction networks for sulfur species to explain the missing sulfur in the gas within dense clouds.Most of these studies used a C/O ratio of 0.7 or lower.We present NSRT(NanShan 26m Radio Telescope)observations of TMC-1 alongside results from time-dependent chemical simulations using an updated chemical network.Our findings highlight the impact of the C/O ratio on the gas-phase evolution of C2S and C3S.The simulation results show that the C/O ratio is an important parameter,playing a fundamental role in determining the gas-phase abundances of sulfur species in dense cores.
查看更多>>摘要：We report the results of a search for radio pulsars in five supernova remnants(SNRs)with the FAST telescope.The observations were made using the 19-beam receiver in"snapshot"mode.The integration time for each pointing was 10 min.We discovered a new pulsar,PSR J1845-0306,which has a spin period of 983.6 ms and a dispersion measure of 444.6±2.0cm-3·pc,in observations of SNR G29.6+0.1.To judge the association between the pulsar and the SNR,further verification is needed.We also re-detected some known pulsars in the data from SNRs G29.6+0.1 and G29.7-0.3.No pulsars were detected in the observations of the other three SNRs.
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