Room temperature spin-orbit torque efficiency and magnetization switching in SrRuO3-based heterostructures

Spin-orbit torques (SOTs) from transition metal oxides (TMOs) in conjunction with magnetic materials have recently attracted tremendous attention for realizing high-efficient spintronic devices. SrRuO3 is a promising candidate among TMOs due to its large and tunable SOT-efficiency as well as high conductivity and chemical stability. However, a further study for benchmarking the SOT-efficiency and realizing SOT-driven magnetization switching in SrRuO3 is still highly desired so far. Here, we systematically study the SOT properties of high-quality SrRuO3 thin film heterostructuring with different magnetic alloys of both IMA and PMA configuration by the harmonic Hall voltage technique. Our results indicate that SrRuO3 possesses pronounced SOT-efficiency of about 0.2 at room temperature regardless of the magnetic alloys, which is comparable to typical heavy metals (HMs). Furthermore, we achieve SOT-driven magnetization switching with a low threshold current density of 3.8x10^10 A/m^2, demonstrating the promising potential of SrRuO3 for practical devices. By making a comprehensive comparison with HMs, our work unambiguously benchmarks the SOT properties and concludes the advantages of SrRuO3, which may bring more diverse choices for SOT applications by utilizing hybrid-oxide/metal and all-oxide systems.Comment: 16 pages, 4 figures, 1 tabl

Anisotropic linear and nonlinear charge-spin conversion in topological semimetal SrIrO3

Over the past decade, utilizing spin currents in the linear response of electric field to manipulate magnetization states via spin-orbit torques (SOTs) is one of the core concepts for realizing a multitude of spintronic devices. Besides the linear regime, recently, nonlinear charge-spin conversion under the square of electric field has been recognized in a wide variety of materials with nontrivial spin textures, opening an emerging field of nonlinear spintronics. Here, we report the investigation of both linear and nonlinear charge-spin conversion in one single topological semimetal SrIrO3(110) thin film that hosts strong spin-orbit coupling and nontrivial spin textures in the momentum space. In the nonlinear regime, the observation of crystalline direction dependent response indicates the presence of anisotropic surface states induced spin-momentum locking near the Fermi level. Such anisotropic spin textures also give rise to spin currents in the linear response regime, which mainly contributes to the fieldlike SOT component. Our work demonstrates the power of combination of linear and nonlinear approaches in understanding and utilizing charge-spin conversion in topological materials.Comment: 18 pages, 5 figure

Glycolate Oxidase Isozymes Are Coordinately Controlled by GLO1 and GLO4 in Rice

Glycolate oxidase (GLO) is a key enzyme in photorespiratory metabolism. Four putative GLO genes were identified in the rice genome, but how each gene member contributes to GLO activities, particularly to its isozyme profile, is not well understood. In this study, we analyzed how each gene plays a role in isozyme formation and enzymatic activities in both yeast cells and rice tissues. Five GLO isozymes were detected in rice leaves. GLO1 and GLO4 are predominately expressed in rice leaves, while GLO3 and GLO5 are mainly expressed in the root. Enzymatic assays showed that all yeast-expressed GLO members except GLO5 have enzymatic activities. Further analyses suggested that GLO1, GLO3 and GLO4 interacted with each other, but no interactions were observed for GLO5. GLO1/GLO4 co-expressed in yeast exhibited the same isozyme pattern as that from rice leaves. When either GLO1 or GLO4 was silenced, expressions of both genes were simultaneously suppressed and most of the GLO activities were lost, and consistent with this observation, little GLO isozyme protein was detected in the silenced plants. In contrast, no observable effect was detected when GLO3 was suppressed. Comparative analyses between the GLO isoforms expressed in yeast and the isozymes from rice leaves indicated that two of the five isozymes are homo-oligomers composed of either GLO1 or GLO4, and the other three are hetero-oligomers composed of both GLO1 and GLO4. Our current data suggest that GLO isozymes are coordinately controlled by GLO1 and GLO4 in rice, and the existence of GLO isozymes and GLO molecular and compositional complexities implicate potential novel roles for GLO in plants

ROR1 Is Expressed in Human Breast Cancer and Associated with Enhanced Tumor-Cell Growth

Receptor-tyrosine-kinase-like orphan receptor 1 (ROR1) is expressed during embryogenesis and by certain leukemias, but not by normal adult tissues. Here we show that the neoplastic cells of many human breast cancers express the ROR1 protein and high-level expression of ROR1 in breast adenocarcinoma was associated with aggressive disease. Silencing expression of ROR1 in human breast cancer cell lines found to express this protein impaired their growth in vitro and also in immune-deficient mice. We found that ROR1 could interact with casein kinase 1 epsilon (CK1ε) to activate phosphoinositide 3-kinase-mediated AKT phosphorylation and cAMP-response-element-binding protein (CREB), which was associated with enhanced tumor-cell growth. Wnt5a, a ligand of ROR1, could induce ROR1-dependent signaling and enhance cell growth. This study demonstrates that ROR1 is expressed in human breast cancers and has biological and clinical significance, indicating that it may be a potential target for breast cancer therapy

Flotation separation of limonite from calcite with sodium oleate: effects of calcite dissolution and addition of sodium pyrophosphate

Limonite is now considered as an important iron ore resource in China due to the rapidly depleting magnetite and haematite reserves. The separation of limonite from calcite by flotation is a problem to be solved, and it was investigated systematically in this paper. Flotation tests show that the recoveries of limonite and calcite are close to 95% within the pH range of 7.5–10.0 using 3 × 10 mol/L sodium oleate as collector. However, the flotation of limonite was depressed by calcium ions generated from the dissolution of calcite in the flotation of a mixture of limonite and calcite. The effects of depression on limonite can be enhanced by adding sodium pyrophosphate. Hence, the separation of calcite from limonite can be finished by reverse flotation. Under the test condition, the limonite–calcite mixture with Fe grade of 28.45% was upgraded to a concentrate with 50.5% Fe and 91.50% Fe recovery

The perception of desertification, its social impact and the adaptive strategies of ecological migrants in the desertification area, China

Based on social influence theory, the Risk-Coping-Social Appraisal model, and data on land desertification, its social influence, and the adaptive measures of 506 households surveyed in Ordos and Bayan Nur, Inner Mongolia, China, we used the Heckman two-stage model and a multinomial logistic model and found the following. First, the perception of land desertification was a prerequisite for eco-migrants to employ adaptive strategies but did not necessarily indicate the adoption of adaptive countermeasures. Second, the social influences eco-migrants experienced at their resettlement site had a significant effect on their ability to employ countermeasures to land desertification. Third, asset variables that reflected migrant's coping ability positively affected perceptions of land desertification and subsequent adaptive countermeasures. To mitigate the negative effects of climate change and land desertification, the local government should encourage migrants to accumulate assets and help migrants to integrate into their new community. This can be achieved by propagandizing information on climate change through a range of channels, diversifying publicity content, and guiding migrants to learn about new technologies and methods for reducing land desertification to minimize related economic losses

Flotation separation of limonite from quartz with sodium oleate: effects of limonite dissolution and addition of sodium hexametaphosphate

The utilisation of limonite ore is potentially important to China as the high quality iron resource, such as magnetite and hematite of high grade, are rapidly depleting, but many detrimental impurities, such quartz and calcite etc, are difficult to upgrade to make suitable concentrates for the blast furnace. The flotation behaviour of limonite, quartz and their mixture by using sodium oleate as collector were studied systematically in this paper. Single-mineral flotation tests showed that the flotation recovery of limonite was much higher than that of quartz in a broad range of pH. However, flotation tests for the mixture of limonite and quartz showed rather poor mineral separation efficiency with the flotation recovery of both minerals being high in froth products. The flotation separation efficiency of limonite from quartz was substantially improved by adding sodium hexametaphosphate (SHMP) as a depressant for quartz flotation. To elucidate these phenomena, the solution species calculation of limonite dissolution and the measurements of iron ions content were carried out. It was found that iron ions or its species released into the pulp from the dissolving of limonite could effectively activate the flotation of quartz but have little influence on the flotation of limonite. In the presence of SHMP, iron ions or its species lost their activating power on quartz flotation which caused by the chemical reaction between SHMP and iron ions or its species, and then removed iron ions or its species from quartz surface into the solution

Exploring new battery knowledge by advanced characterizing technologies

Abstract Exploration of science and technologies represents human's thirst for new knowledge and new life. Presently, we are in a stage of transferring the use of fossil fuels to renewable energy, which urgently calls for new energy materials and techniques beyond the boundary of human knowledge. On the way of scrutinizing these materials and surmounting the bottleneck of their performances, characterizing technologies are of critical importance in enabling the revealing of materials regarding their structural and chemical information, eventually establishing the correlations between microstructures and properties at the multiscale levels. Regrettably, traditional characterizations are hard to simultaneously probe electrochemistry with these chemical and physical structural evolutions, especially under operando conditions, or offer high‐resolution images of materials sensitive to electron‐beam irradiation. To this end, various advanced characterizing and diagnosing technologies recently developed, such as transmission X‐ray microscopy and cryo‐transmission electron microscopy, have demonstrated their benefits in understanding the energy storage behaviors of high‐performance energy materials (such as layered transition oxide cathode and Li metal anode). Benefited from new knowledge, the progress of high‐capacity electroactive materials is significantly accelerated. Here, we timely review the breakthroughs in emerging techniques and discuss how they guide the design of future battery materials to achieve the ultimate carbon neutrality