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71.
Tailoring Magnetic Properties of MAX Phases,a Theoretical Investigation of (Cr2Ti)AlC2 and Cr2AlC
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Jiemin Wang Zhimou Liu Haibin Zhang Jingyang Wang 《Journal of the American Ceramic Society》2016,99(10):3371-3375
(Cr2Ti)AlC2 is a newly discovered MAX phase with ordered occupations of Ti and Cr atoms on M sites. The Cr‐containing MAX phase is expected showing magnetic property, which provides functional applications in spintronics and as self‐monitoring smart coating. The magnetic states of (Cr2Ti)AlC2 are predicted by GGA and GGA + U methods and compared to those of Cr2AlC. The ground states are predicted as FM or AFM‐XX configurations depending on the calculation methods. Analysis of the electronic structure shows that the magnetic moments mainly originate from the net spins of Cr 3d valence electrons, whereas the contribution of other atoms is negligible. The calculated magnetic moments of Cr atoms in (Cr2Ti)AlC2 are higher than those in Cr2AlC due to the larger distance between the out‐plane Cr atoms separated by the intercalated nonmagnetic Ti–C slab. This work provides an insight on tailoring magnetic properties of MAX phases by modifying the crystal structure. 相似文献
72.
High‐Temperature Neutron Diffraction,Raman Spectroscopy,and First‐Principles Calculations of Ti3SnC2 and Ti2SnC
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Grady W. Bentzel Michael Naguib Nina J. Lane Sven C. Vogel Volker Presser Sylvain Dubois Jun Lu Lars Hultman Michel W. Barsoum El'ad N. Caspi 《Journal of the American Ceramic Society》2016,99(7):2233-2242
Herein, we report—for the first time—on the additive‐free bulk synthesis of Ti3SnC2. A detailed experimental study of the structure of the latter together with a secondary phase, Ti2SnC, is presented through the use of X‐ray diffraction (XRD), and high‐resolution transmission microscopy (HRTEM). A previous sample of Ti3SnC2, made using Fe as an additive and Ti2SnC as a secondary phase, was studied by high‐temperature neutron diffraction (HTND) and XRD. The room‐temperature crystallographic parameters of the two MAX phases in the two samples are quite similar. Based on Rietveld analysis of the HTND data, the average linear thermal expansion coefficients of Ti3SnC2 in the a and c directions were found to be 8.5 (2)·10?6 K?1 and 8.9 (1)·10?6 K?1, respectively. The respective values for the Ti2SnC phase are 10.1 (3)·10?6 K?1 and 10.8 (6)·10?6 K?1. Unlike other MAX phases, the atomic displacement parameters of the Sn atoms in Ti3SnC2 are comparable to those of the Ti and C atoms. When the predictions of the atomic displacement parameters obtained from density functional theory are compared to the experimental results, good quantitative agreement is found for the Sn atoms. In the case of the Ti and C atoms, the agreement is more qualitative. We also used first principles to calculate the elastic properties of both Ti2SnC and Ti3SnC2 and their Raman active modes. The latter are compared to experiment and the agreement was found to be good. 相似文献
73.
MAX相材料有作为事故容错燃料(accident tolerant fuel,ATF)包壳材料的潜力,为了全面了解MAX相材料在模拟正常工况下的腐蚀行为,使用基体为Ti3SiC2的MAX相陶瓷管材于400℃/10.3 MPa过热蒸气,360℃/18.6 MPa去离子水、3.5μL/L Li+1000μL/L B溶液和70μL/L Li溶液4种不同的水化学条件中进行腐蚀试验,采用XRD、SEM和FIB/TEM观察分析腐蚀前后样品的显微组织、晶体结构和成分。结果表明,Ti3SiC2管材在4种条件下的腐蚀速率均远高于参比Zr-4合金,腐蚀后主要检测到腐蚀产物TiO2,且其表面疏松多孔,未形成保护性的氧化膜。 相似文献
74.
随着控制技术的发展,控制系统越做越复杂,由单片机构建的控制系统已经由一个单片机组成的系统发展到多个单片机组成的多机控制系统和多个单片机组成的网络系统。在工业监控和民用产品中单片机系统使用的越来越多。随着技术的发展和市场竞争的加剧,生产厂家除了考虑到产品的性能也要考虑到产品成本。Microehip公司的PIC16C57是一款性价比较高的单片机。由该单片机建立起来的系统成本大大降低。本文介绍了一种由PIC16C57单片机建立起来的分级总线型网络系统,系统可以用于工业系统监控和民用楼宇监控系统,该网络系统在硬件和软件上都采取了特别的保护措施,系统具有非常好的稳定性和可靠性。 相似文献
75.
《Journal of the European Ceramic Society》2022,42(8):3415-3426
Herein, a reliable diffusion bonding of Ti3Si(Al)C2 ceramic is achieved by applying Au foil as an interlayer at 650 °C for 30 min with an axial pressure of 20 MPa. This novel method significantly decreases the bonding temperature, which is about 150 °C lower than the lowest bonding temperature from current research to the best of our knowledge. Maximum shear strength of 58 MPa is achieved at 650 °C among the bonding temperature range of 600 °C~800 °C. The microstructure evolution mechanism and the relationship between microstructure and mechanical property are discussed. The facile mutual diffusion of Au with de-intercalated Al and Si from Ti3Si(Al)C2 is considered critical in achieving sound interfacial bonding. 相似文献
76.
77.
如何为便携式产品供电一直是备受关注的话题,各种新型的电池及电源管理器件的应用,为人们的生产生活带来巨大方便,在便携式仪器应用上,以可充电电池的应用较为广泛,但是在某些不方便充电的特殊应用场合,充电式电源的便利性就会受到限制,本文便是探讨如何利用可充电电池与传统的碱性干电池相结合,为便携式仪器供电. 相似文献
78.
79.
针对传统的IMU信号采集系统尺寸大、成本高和集成度低等不足,介绍了以DSP为核心的集成式IMU信号采集系统的解决方案,详细阐述了系统硬件实现方案和软件实时误差校正算法.该系统具有速度快、体积小、功耗低等特点. 相似文献
80.
基于MAX1452的压力传感器温度补偿 总被引:1,自引:0,他引:1
传感器精度是影响电-气比例调压阀性能的重要因素。以硅压阻式传感器为例,介绍传感器存在的温度误差,着重阐述采用MAX1452补偿其温度误差的原理,并系统介绍温度补偿的操作流程和校正系数的选择计算,通过实例分析验证压阻传感器经MAX1452补偿后,其温度误差可明显降低。 相似文献