Search

The tunnelling electric current passing through a magnetic tunnel junction (MTJ) is strongly dependent on the relative orientation of magnetizations in ferromagnetic electrodes sandwiching an insulating barrier, rendering efficient readout of spintronics devices1–5. Thus, tunnelling magnetoresistance (TMR) is considered to be proportional to spin polarization at the interface1 and, to date, has been studied primarily in ferromagnets. Here we report observation of TMR in an all-antiferromagnetic tunnel junction consisting of Mn3Sn/MgO/Mn3Sn (ref. 6). We measured a TMR ratio of around 2% at room temperature, which arises between the parallel and antiparallel configurations of the cluster magnetic octupoles in the chiral antiferromagnetic state. Moreover, we carried out measurements using a Fe/MgO/Mn3Sn MTJ and show that the sign and direction of anisotropic longitudinal spin-polarized current in the antiferromagnet7 can be controlled by octupole direction. Strikingly, the TMR ratio (about 2%) of the all-antiferromagnetic MTJ is much larger than that estimated using the observed spin polarization. Theoretically, we found that the chiral antiferromagnetic MTJ may produce a substantially large TMR ratio as a result of the time-reversal, symmetry-breaking polarization characteristic of cluster magnetic octupoles. Our work lays the foundation for the development of ultrafast and efficient spintronic devices using antiferromagnets8–10.

Electrical control of a magnetic state of matter lays the foundation for information technologies and for understanding of spintronic phenomena. Spin-orbit torque provides an efficient mechanism for the electrical manipulation of magnetic orders

High interfacial transparency is vital to achieve efficient spin-charge conversion for ideal spintronic devices with low energy consumption. However, in traditional ferromagnetic/nonmagnetic heterojunctions, the interfacial Rashba spin-orbit coupling brings about spin memory loss (SML) and two-magnon scattering (TMS), quenching spin current crossing the heterointerfaces. To address the intrinsic deficiency of heterointerface, we design a ferromagnetic FeRh/antiferromagnetic FeRh spin homojunction for efficient spin-charge conversion, verified by a high interfacial transparency of 0.75 and a high spin torque efficiency of 0.34 from spin pumping measurements. First-principles calculations demonstrate that the interfacial electric field of homojunction is two orders of magnitude smaller than that of traditional heterojunction, producing negligible interfacial spin-orbit coupling to drastically reduce SML and TMS. Our spin homojunction exhibits potential and enlightenment for future energy-efficient spintronic devices.

High lithium ion transference number (tLi+) is one of the requirements of polymer electrolytes for utilization in lithium secondary batteries. Herein, graphene oxide (GO) is used as a filler to fabricate the homogeneous gel polymer electrolyte (GPE) for pursuing high tLi+. The effect of GO on the whole properties of gel polymer electrolytes including conductivity, lithium ion transference number, electrochemical window, electrochemical stability, and cycling performance are explored. Impressively, the GPE containing 0.3 wt% of GO (labeled as GPE-0.3%) demonstrates a high lithium ion transference number of 0.79 and improved electrochemical stability. The LFP/Li battery with GPE-0.3% as the separator shows excellent electrochemical cycle stability and Coulomb efficiency at 25 °C. The discharge specific capacity retention rate of this battery is 94.4% after 100 cycles at 0.2C. All these features make the gel polymer electrolyte useful as a separator of lithium metal batteries for high-performance lithium ion conductors, which exhibits high safety.

Magnetic skyrmions are vortex-like spin textures with nontrivial spin topology and novel physical properties that show promise as an essential building block for novel spintronic applications. Skyrmions in synthetic antiferromagnets (SAF) have been proposed long-term to have many advantages than those in ferromagnetic materials, which suffer from fundamental limits for size and efficient manipulation. Thus, experimental realization of skyrmions in SAF is intensely pursued. Here we show the observation of zero-field stable magnetic skyrmions at room temperature in SAF [Co/Pd]/Ru/[Co/Pd] multilayers with Lorentz transmission electron microscope, where uncompensated moments of the SAF provide a medium for the skyrmion characterization. Isolated skyrmions and high-density skyrmions via magnetic field and electromagnetic coordinated methods have been observed, respectively. These created high-density skyrmions maintain at zero-field even when both the current and magnetic field are removed. The use of skyrmions in SAF would advance the process toward practical nonvolatile memories based on spin topology.

Approaches of internationalization of higher education (HE) have stimulated numerous countries to concurrently formulating innovative policies and strategies to make their higher educational institutions (HEIs) globally competitive. This has the aim to attract more international students and talents. In the view of this, many countries adopt different approaches to internationalize their HEIs. It is of this background the study has explored how the Chinese government’s strategy and approaches boost up the attraction of international students to Chinese HE and to augment their internationalization practices. The study adopted qualitative research methodology, specifically employed interview and document analysis. Fifteen students were interviewed from three universities in Beijing. The study showed the role of the Chinese government and their strategies through scholarship provision and other programs to beef up the internationalization of Chinese HEIs. The study concluded by recommending that the HEIs should pay much attention to the quality education to international students not only been enthused with the quantitative nature of internationalization.

Sensitive and specific detection of nucleic acids or proteins, which act as biomarkers, is of great importance in disease diagnosis. By combing the concept and operation of an endonuclease-assisted target-responsive amplification method and peroxidase-mimic DNAzyme generated by terminal deoxynucleotidyl transferase (TdT), a novel and facile colorimetric biosensor was developed for DNA and protein. Target DNA and thrombin were chosen as representative biomolecules. The production of cleavage fragments can only be triggered by specific target binding and the following nicking process, which do not occur spontaneously. In the signal collection part, numerous guanine-rich DNA were produced through the prolongation of cleavage fragments by TdT and formed highly effective DNAzyme with hemin. In this novel amplification method, we succeeded in realizing sensitive and specific detection of target DNA and thrombin. Under optimal conditions, target DNA can be detected as low as 1 pM, and thrombin with a detection limit of 100 pM. The method also proves the potential versatility and feasibility of TdT-generated DNAzyme in various bio-analyses.

This paper uses panel data from 9381 samples of listed companies in China’s A-share market from 2013 to 2018 to regress. Based on the theoretical analysis, this article explores the relationship between China’s corporate social responsibility and the stock market crash risk, adding variables to examine the moderating effects of corporate social capital. Through the empirical research, this paper finds the conclusion that there is a negative correlation between corporate social responsibility and the risk of stock price crash. At the same time, corporate social capital has the moderating effects in the relationship between corporate social responsibility and the stock price crash risk. According to the conclusions, this article puts forward the suggestion that enterprises should enhance their awareness of social responsibility and actively fulfill their social responsibilities, and management should also focus on accumulating social capital.

Detoxifying materials against chemical warfare agents (CWAs) and their simulants are highly desired for proper handling of contamination by and destruction of CWAs. Herein, we report a facile layer-by-layer fabrication of core-shell Fe3O4@UiO-66-NH2 and its application in fast degradation of CWA simulants. The Fe3O4@UiO-66-NH2 composite was prepared through a layer-by-layer epitaxial growth strategy, by alternately immersing Fe3O4 nanoparticles in ethanol solutions of a metal node [Zr6O4(OH)4]12+ precursor and organic linkers [NH2-BDC, 2-aminoterephthalic acid], respectively, and separating using a magnet. As confirmed by characterization results, the Fe3O4@UiO-66-NH2 composites with 24.4 μmol/g Zr6 node content showed a well-defined core-shell structure as well as good thermal and chemical stability. These core-shell magnetic metal-organic frameworks (MOFs) were further tested in the catalytic hydrolysis of dimethyl-4-nitrophenyl phosphate (a nerve agent simulant) and demonstrated 36 times higher catalytic activity than the UiO-66-NH2 powder due to their highly defective surface, high percentage of MOFs on the surface, and their rich mesoporous structure. Since magnetism was retained after the coating of MOFs, Fe3O4@UiO-66-NH2 could be easily recovered and reused after catalysis.

Aim To analyze the effect of preserving the left colic artery (LCA) on long-term oncologic outcomes during laparoscopic low anterior resection of rectal cancer. Methods Clinicopathological and follow-up patients undergoing laparoscopic low anterior resection of rectal cancer in general surgery department of Guangdong Provincial People's Hospital from January 2014 to December 2015 were retrospectively collected. According to the difference surgical methods of inferior mesenteric artery (IMA), 159 cases were divided into the LCA preservation group and 225 cases in the LCA non-preservation group. The 5-year rates of overall survival (OS) and disease-free survival (DFS) were compared between two group. Results 384 patients were included in final analysis. Anastomotic leakage occurred in 7 patients (4.4%) in the LCA preservation group and in 16 patients (7.1%) in the LCA non-preservation group. The follow-up rate was 91.2% (145/159) during 5–60 months in LCA preservation group, and 89.8% (202/225) during 5–60 months in the LCA non-preservation group. The number of patients who developed death, local recurrence and metastasis were 59 (37.1%), 13 (8.2%) and 60 (37.7%) in the LCA preservation group, and 86 (38.2%), 20 (8.9%) and 92 (40.9%) in the LCA non-preservation group, without significant differences (all P ༞ 0.05). The 5-year OS and DFS rates were 69.0% and 59.3% in the LCA preservation group, and 68.8% and 55.9% in the LCA non-preservation group, without significant differences (all P ༞ 0.05). After stratification by TNM Stage, the difference on 5-year OS rates and DFS rates of I stage, II stage and III stage in two groups were no significant as well (all P ༞ 0.05). Conclusions The long-term oncologic outcomes of laparoscopic low anterior resection of rectal cancer with preservation of the LCA are comparable with ligation at origin of IMA.

Background There is uncertainty in the literature about preserving the left colic artery (LCA) during low anterior resection for rectal cancer. We analyzed the effect of preserving the LCA on long-term oncological outcomes. Methods We retrospectively collected clinicopathological and follow-up details of patients who underwent low anterior resection for rectal cancer in the General Surgery Department of Guangdong Provincial People’s Hospital, from January 2014 to December 2015. Cases were divided into low ligation (LL), LCA preserved, or high ligation (HL), LCA not preserved, of the inferior mesenteric artery. The 5-year overall survival (OS) and disease-free survival (DFS) rates were compared between the two groups. Results Altogether, there were 221 and 295 cases in the LL group and HL groups, respectively. Operating time in the LL group was significantly longer than in the HL group (224.7 vs. 211.7 min, p = 0.039). Postoperative 30-day mortality, early complications including anastomotic leakage showed no significant differences between the LL and HL groups (postoperative 30-day mortality, 0.9% LL, 1.4% HL, p = 0.884; early complications, 41.2% LL, 38.3% HL, p = 0.509; anastomotic leakage 8.6% LL, 13.2% HL, p = 0.100). The median follow-up periods were 51.4 (7–61) months in the LL group and 51.2 (8–61) months in the HL group. During follow-up, the percentages of patients who died, had local recurrence, or had metastases were 39.8, 7.7, and 38.5%, respectively, in the LL group and 39, 8.5, and 40%, respectively, in the HL group; these differences were not significant (all p > 0.05). The 5-year OS and DFS were 69.6 and 59.6% in the LL group, respectively, and 69.1 and 56.2% in the HL group, respectively; these differences were not significant (all p > 0.05). After stratification by tumor-node-metastasis stage, the difference between the 5-year OS and DFS for stages I, II, and III cancer were not significant (all p > 0.05). Conclusions The long-term oncological outcomes of LL group are comparable with HL group. LL cannot be supported due to the absence of lower complication rates and the longer operating times.

The discovery of the spin Hall effect1 enabled the efficient generation and manipulation of the spin current. More recently, the magnetic spin Hall effect2,3 was observed in non-collinear antiferromagnets, where the spin conservation is broken due to the non-collinear spin configuration. This provides a unique opportunity to control the spin current and relevant device performance with controllable magnetization. Here, we report a magnetic spin Hall effect in a collinear antiferromagnet, Mn2Au. The spin currents are generated at two spin sublattices with broken spatial symmetry, and the antiparallel antiferromagnetic moments play an important role. Therefore, we term this effect the ‘antiferromagnetic spin Hall effect’. The out-of-plane spins from the antiferromagnetic spin Hall effect are favourable for the efficient switching of perpendicular magnetized devices, which is required for high-density applications. The antiferromagnetic spin Hall effect adds another twist to the atomic-level control of spin currents via the antiferromagnetic spin structure. A magnetic spin Hall effect is reported in the collinear antiferromagnet Mn2Au.

The ultrafast electron transport is central to the requirement of all-electrically controlled spintronics in metallic collinear antiferromagnetic (AFM) ${\mathrm{Mn}}_{2}\mathrm{Au}$ thin films within the terahertz (THz) range. Here we use the THz time-domain spectroscopy to measure the conductivity spectra of ${\mathrm{Mn}}_{2}\mathrm{Au}$ thin films with different thicknesses and temperatures. We demonstrate an onset of carrier localization in ${\mathrm{Mn}}_{2}\mathrm{Au}$ with decreasing the film thickness from 15 to 5 nm. By using optical pump-THz probe spectroscopy, we found the surface trapping states in the thinnest ${\mathrm{Mn}}_{2}\mathrm{Au}$ film limit its photoconductivity significantly. The DC conductivity and scattering time become larger and longer with decreasing temperature for all samples, which suggests that ${\mathrm{Mn}}_{2}\mathrm{Au}$ behaves in a typical metallic fashion. The THz optical and conductivity properties of ${\mathrm{Mn}}_{2}\mathrm{Au}$ films will advance our understanding of ultrafast electronic transport processes in AFM ${\mathrm{Mn}}_{2}\mathrm{Au}$ thin films.

Ferrimagnetic insulators (FiMI) have been intensively used in microwave and magneto-optical devices as well as spin caloritronics, where their magnetization direction plays a fundamental role on the device performance. The magnetization is generally switched by applying external magnetic fields. Here we investigate current-induced spin-orbit-torque switching of the magnetization in ${\mathrm{Y}}_{3}{\mathrm{Fe}}_{5}{\mathrm{O}}_{12}$ ($\mathrm{YIG}$)/$\mathrm{Pt}$ bilayers with in-plane magnetic anisotropy, where the switching is detected by spin Hall magnetoresistance. Reversible switching is found at room temperature for a threshold current density of ${10}^{7}\phantom{\rule{0.1em}{0ex}}\mathrm{A}\phantom{\rule{0.1em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}2}$. The $\mathrm{YIG}$ sublattices with antiparallel and unequal magnetic moments are aligned parallel or antiparallel to the direction of current pulses, which is consistent to the N\'eel-order switching in an antiferromagnetic system. It is proposed that such a switching behavior may be triggered by the antidamping torque acting on the two antiparallel sublattices of FiMI. Our finding not only broadens the magnetization switching by electrical means and promotes the understanding of magnetization switching, but also paves the way for all-electrically modulated microwave devices and spin caloritronics with low power consumption.

There is a great matter of controversies whether some of these synchronous metastatic colorectal cancer patients can benefit from palliative primary tumor resection (pPTR) and there is still no reported randomized control trial to address this issue.Patients with microscopically proven metastatic colorectal cancer were identified within the SEER database (2010-2016). Patients were propensity matched 1:1 into pPTR and non-surgery groups and among the matched cohort, the univariable and multivariable Cox proportional hazards regression models were performed to identify predictors of survival. Median survival was calculated by using the Kaplan-Meier method.Of 21,405 colorectal cancer patients diagnosed with synchronous liver and/or lung metastases, 7386 were identified in the matched cohort. The median overall survival was 12.0 months, 22.0 months in the non-surgery, surgery groups, respectively (p 0.001) and the corresponding median cancer-specific survival was 13.0 months, 22.0 months, respectively (p 0.001). Multivariable Cox regression analysis demonstrated that surgery was independently associated with improved overall survival (hazard ratio, 0.531) as well as cancer-specific survival (hazard ratio, 0.516). In stratified analyses by primary site and patterns of distant metastases, those patients with pPTR had better prognosis. In addition, stratified analysis revealed that trimodality therapy was linked with the greatest therapeutic effect followed by addition of chemotherapy to pPTR.pPTR may offer some therapeutic benefits among carefully selected patients, and surgery-based multimodality therapy was associated with better survival.

Using a non-alphabetic language (e.g., Chinese), the present study tested a novel view that semantic information at the sublexical level should be activated during handwriting production. Over 80% of Chinese characters are phonograms, in which semantic radicals represent category information (e.g., 'chair,' 'peach,' 'orange' are related to plants) while phonetic radicals represent phonetic information (e.g., 'wolf,' 'brightness,' 'male,' are all pronounced /lang/). Under different semantic category conditions at the lexical level (semantically related in Experiment 1; semantically unrelated in Experiment 2), the orthographic relatedness and semantic relatedness of semantic radicals in the picture name and its distractor were manipulated under different SOAs (i.e., stimulus onset asynchrony, the interval between the onset of the picture and the onset of the interference word). Two questions were addressed: (1) Is it possible that semantic information could be activated in the sublexical level conditions? (2) How are semantic and orthographic information dynamically accessed in word production? Results showed that both orthographic and semantic information were activated under the present picture-word interference paradigm, dynamically under different SOAs, which supported our view that discussions on semantic processes in the writing modality should be extended to the sublexical level. The current findings provide possibility for building new orthography-phonology-semantics models in writing.

Supplemental material, sj-pdf-1-jbf-10.1177_2280800020963471 for Fabrication of pH-sensitive graphene oxide–Benazepril carrier as biosafety controlled release systems by Tianxiong Liu, Yujiao Li, Xianzhe Chen, Xiaoming Zhao, Jianfang Wang and Dongyi Zhang in Journal of Applied Biomaterials & Functional Materials

We demonstrate spin-orbit torque (SOT) switching of amorphous CoTb single layer films with perpendicular magnetic anisotropy (PMA). The switching sustains even the film thickness is above 10 nm, where the critical switching current density keeps almost constant. Without the need of overcoming the strong interfacial Dzyaloshinskii-Moriya interaction caused by the heavy metal, a quite low assistant field of ~20 Oe is sufficient to realize the fully switching. The SOT effective field decreases and undergoes a sign change with the decrease of the Tb-concentration, implying that a combination of the spin Hall effect from both Co and Tb as well as an asymmetric spin current absorption accounts for the SOT switching mechanism. Our findings would advance the use of magnetic materials with bulk PMA for energy-efficient and thermal-stable non-volatile memories, and add a different dimension for understanding the ordering and asymmetry in amorphous thin films., Comment: 17 pages, 4 figures, Phys. Rev. B 101, 214418 (2020)

Detoxifying materials against chemical warfare agents (CWAs) and their simulants are highly desired for proper handling of contamination by and destruction of CWAs. Herein, we report a facile layer-by-layer fabrication of core-shell Fe

The spin-orbit torque (SOT) switching of trilayers with two heavy-metal layers on the same side of the ferromagnetic metal layer was studied, realizing tunable spin Hall angle, domain-wall motion, and Dzyaloshinskii-Moriya interaction. However, systematic research on the magnetoresistance in such structures is still lacking. In this work, we investigate the anisotropic magnetoresistance (AMR) and the spin Hall magnetoresistance (SMR) by inserting an ultrathin Ir layer (${t}_{\mathrm{Ir}}\ensuremath{\le}1.4\phantom{\rule{0.16em}{0ex}}\mathrm{nm}$) into Ta/CoFeB. The Ir layer with the thickness larger than 0.4 nm can transform the AMR from positive to negative, which is attributed to the electronic structure of Ir. This process realizes the interfacial modulation of AMR, which is generally considered as a bulk property. The SMR ratio decreases first and then increases with increasing Ir thickness, producing the minimum and maximum at ${t}_{\mathrm{Ir}}=0.3\phantom{\rule{0.16em}{0ex}}\mathrm{nm}$ and ${t}_{\mathrm{Ir}}=0.9\phantom{\rule{0.16em}{0ex}}\mathrm{nm}$, respectively, which reflects the ultrasmall spin-diffusion length (0.5 nm) and strong spin-memory loss in Ir. Further analyses combined with the SOT switching measurements unravel the existence of the anomalous Hall magnetoresistance, implying the non-negligible spin accumulation due to the anomalous Hall effect of the ferromagnetic metal. The combination of a large negative AMR and comparatively smaller SMR results in a negative planar Hall resistance. Our findings enrich the understanding of the magnetoresistances of heavy-metal/ferromagnetic metal trilayer systems.

Electric field control of spin–orbit torque in ferromagnets1 has been intensively pursued in spintronics to achieve efficient memory and computing devices with ultralow energy consumption. Compared with ferromagnets, antiferromagnets2,3 have huge potential in high-density information storage because of their ultrafast spin dynamics and vanishingly small stray field4–7. However, the manipulation of spin–orbit torque in antiferromagnets using electric fields remains elusive. Here we use ferroelastic strain from piezoelectric materials to switch the uniaxial magnetic anisotropy in antiferromagnetic Mn2Au films with an electric field of only a few kilovolts per centimetre at room temperature. Owing to the uniaxial magnetic anisotropy, we observe an asymmetric Neel spin–orbit torque8,9 in the Mn2Au, which is used to demonstrate an antiferromagnetic ratchet. The asymmetry of the Neel spin–orbit torque and the corresponding antiferromagnetic ratchet can be reversed by the electric field. Our finding sheds light on antiferromagnet-based memories with ultrahigh density and high energy efficiency. A ferroelectric material is used to switch the uniaxial magnetic anisotropy of an antiferromagnet, with implications for antiferromagnetic spintronics.

Current-induced spin-orbit torque (SOT) is attracting increasing interest and exciting significant research activity. We aim to provide a comprehensive review of recent progress in SOT in various materials. The intrinsic correlation between the heterostructure and SOT behaviors is emphasized. We first present a brief summary of the spin-orbit coupling in inversion-asymmetric magnetic systems and describe the discovery, classification and development of SOT. Then we focus on the characterization techniques and classification of SOT from the viewpoint of materials, including both spin sources and magnetic functional layers. In the third part, the mechanisms of SOT are discussed in detail, including spin Hall effect, Rashba effect, and emerging new mechanisms. The fourth part illustrates SOT in subdivided magnetic systems, including heavy metal combined with ferromagnets, ferrimagnets and antiferromagnets, and systems with topological insulators and single layer magnets. The fifth part presents typical performances of SOT, including the modulation, improvement, and field-free switching through material design, and discusses its promising applications for non-volatile SOT-magnetic random access memory and other device configurations. We conclude with a discussion of the challenges and future prospects of SOT, which will inspire more in-depth research and advance the practical applications.

The technique of gob-side entry retaining has been widely used in underground coal seam mining, where the headgate of current panel is retained and reused for adjacent next panel mining. To evaluate the adaptation of this technique, six geological factors, including coal seam dip angle, mining height, cover depth, thickness influence coefficient of immediate roof (TICIR), lithology of immediate roof and roof integrity, were determined, and their distribution characteristics in practice and weight analysis using 1–9 scale method of analytic hierarchy process (AHP) were used to apportion weight of indicators. It is found that, among all indicators, the dip angle had the highest weight while the buried depth had the lowest weight, indicating that the coal seam dip angle is the most important factor. Moreover, five adaptive grades were classified and gob side support strategy for entry of each grade was provided according to technical standards, statistical information and field experience. Finally, fuzzy comprehensive evaluation was used to weight the gateway adaptive grade index. The adaptation assessment grades may be evaluated as reasonable and scientific by six validated cases. Therefore the proposed method and framework can be considered as a supplementary tool in design of gob-side entry retaining.

We investigate the influences of film composition, tuned by argon growth pressure and palladium doping, on antiferromagnetic to ferromagnetic transition temperatures of FeRh films. Employing complementary characterizations we show that the CsCl-type FeRh grows on MgO (100) substrate epitaxially with a controllable transition temperature. Lower argon pressure, a suitable palladium doping are found to effectively decrease the transition temperature. In addition, the exploration about the influence of post-annealing time on un-doped FeRh films indicates that annealing procedure is helpful to improve the growth quality. The optimized growth parameter provides an opportunity to deposit ultrathin FeRh films (5 nm) with a clear antiferromagnetic to ferromagnetic transition. The manipulation of the transition temperature of FeRh would advance its use in antiferromagnetic spintronics.

Antiferromagnets have drawn increasing attention in the last decade, for their advantages such as no stray field and ultrafast spin dynamics, giving rise to potential applications on high-density storage and high frequency. We summarize the recent progress on the control of antiferromagnetic moments by electrical methods, including both electric current and electric field, which are important steps for the integration of antiferromagnets toward high-density data storage. Several methods for distinguishing antiferromagnetic moments switching and artifacts are mentioned here. Then, we focus on the explorations of antiferromagnetic spin pumping and ultrafast spin dynamics. Such investigations would pave the way for applications with high frequency. Besides, the magnon transport in antiferromagnets is briefly introduced, which might be a basis of the antiferromagnetic logic. We conclude with a discussion of challenges and future prospects in antiferromagnetic spintronics, which would stimulate in-depth studies and advance practical applications.

Rich magnetic phase transition makes the antiperovskite manganese nitride Mn3AN family an ideal platform to explore the anomalous Hall effect (AHE) with different magnetic configurations. Here, we report the observation of AHE signals up to room temperature in antiferromagnetic (AFM) (001)-oriented Mn3SnN thin films. AHE signals, originated from the Berry curvature, can be controlled by the growth-induced biaxial strain, which leads to the modulation of noncollinear AFM configurations. A relatively large biaxial strain could enhance AHE signals ascribed to the canted AFM structure induced by the piezomagnetic effect. Our findings advance the effective utilization of the AHE in AFM spintronics.

The coercive field of ferromagnets generally increases with decreasing the sample size to hundreds of nanometers mainly because of the (edge) defect pinning. We investigate size-dependent anomalous Hall effect (AHE) in ( 11 2 ¯ 0 )-oriented noncollinear antiferromagnetic Mn3Sn films. The switching field (coercive field) of the AHE decreases abruptly when the width of the Hall bar decreases to hundreds of nanometers, giving rise to the reduced coercive field from 445 to 30 mT for Hall bar with width from 2 μm to 100 nm. This observation is in contrast to the ferromagnetic counterpart. The transition from a multidomain to single domain-like mode and the reduction of Neel temperature are proposed to explain the coercivity variation. Our finding provides a promising candidate for the device miniaturization and adds a different dimension to antiferromagnetic spintronics.