Combustion synthesis is a novel technique that utilizes the exothermic heat of a chemical reaction to maintain the reaction and to rapidly prepare materials. But, hitherto, none of unified criterion for the validation of combustion synthesis has been proposed. Herein, we proposed the conditions need to be met. In terms of kinetics, at the adiabatic temperature (Tad), the diffusion distance of atoms
燃烧合成是一种利用化学反应的放热来维持反应并快速制备材料的新技术。但是,迄今为止,尚未提出用于验证燃烧合成的统一标准。在此,我们提出了需要满足的条件。就动力学而言,在绝热温度(T ad)下,原子的扩散距离(升Ť广告)在0.1 s内应大于反应物的粒径(d), 那是, 升Ť广告≥d。对于满足T ad / T m,L的系统≥1(其中T m,L是反应物的低熔点成分的熔点),液相的存在将原子的扩散距离从纳米显着增加到数十微米,从而成为标准升Ť广告≥d简化为T ad / T m,L≥在大多数情况下为1。在热力学方面,系统需要确保反应成分处于激活状态,即T ad / T m,H ≥0.7,其中T m,H是高熔点组分的熔点。本研究提出的SHS反应标准进一步提高了对SHS反应的理论理解,并为探索二元和多组分化合物的超快合成提供了指导。
Progress on phase equilibria of the Al Si Zr system at 700 and 900 °C
作者:Ya Liu、Maoyou Tang、Changjun Wu、Jianhua Wang、Xuping Su
DOI:10.1016/j.jallcom.2016.09.142
日期:2017.2
Zr system were investigated using equilibrated alloys. All alloys were studied by X-ray powder diffraction, scanning electron microscopy and energy dispersive spectroscopy. The ternary phase τ 1 was found at 700 and 900 °C, while the τ 2 phase was only identified at 900 °C. 12 three-phase regions were experimentally determined in isothermal sections of the Al Si Zr system at both 700 and 900 °C. The
摘要 使用平衡合金研究了 Al Si Zr 系统的相平衡。通过 X 射线粉末衍射、扫描电子显微镜和能量色散光谱对所有合金进行了研究。三元相 τ 1 在 700 和 900 °C 下被发现,而 τ 2 相仅在 900 °C 下被发现。在 700 和 900 °C 的 Al Si Zr 系统的等温截面中,通过实验确定了 12 个三相区域。Si在Al Zr侧的中间相和溶液相(即Al 3 Zr、Al 2 Zr、Al 3 Zr 2 、AlZr 3 、α-Al和(Zr))中的溶解度是有限的,而Al在Al Zr侧的溶解度是有限的。 Si Zr 金属间化合物(Si 2 Zr 3 相除外)是相反的。此外,αSiZr 相中的 Al 在 900 °C 时从 700 °C 时的 10.3 at.% 降至 0.5 at.%。
The crystal chemistry of ZrSi
作者:Tyra C. Douglas、Matthew A. Davenport、Eslam M. Elbakry、Jared M. Allred
DOI:10.1016/j.jssc.2022.123648
日期:2022.12
Reported is a revised crystal structure of β–ZrSi (TlI/CrB structure type), correcting the atomic position and bond distances. The Si–Si bond length has been modified substantially from 2.723(6) Å to 2.4411(8) Å. The β-ZrSi single crystals were grown from an arc-melted button, and were characterized using single crystal X-ray diffraction. A survey of the TlI/CrB structure type shows that changes to
报告了修改后的β -ZrSi 晶体结构(TlI/CrB 结构类型),修正了原子位置和键距。Si-Si 键长已从 2.723(6) Å 大幅修改为 2.4411(8) Å。β -ZrSi 单晶由电弧熔化的纽扣生长,并使用单晶 X 射线衍射进行表征。对 TlI/CrB 结构类型的调查表明,更改命名法将很有用,将其分为四种化学上不同的亚型:TlI、CrB、CaSi 和 ThCo。β -ZrSi 是 CaSi 亚型的一个例子。α-ZrSi结晶成相关的FeB结构类型,这里也分为FeB、CeSi和YNi亚型。借助 Zintl 概念和线性松饼-锡轨道 (LMTO) 基础中的电子结构计算,电子计数对 CaSi 和 CeSi 亚型的相对相位稳定性的影响得以合理化。
A novel preparation of Zr–Si intermetallics by electrochemical reduction of ZrSiO<sub>4</sub> in molten salts
作者:Hongxia Liu、Yanqing Cai、Qian Xu、Qiushi Song、Huijun Liu
DOI:10.1039/c5nj01896j
日期:——
Zr–Si intermetallics with a designed composition were prepared by direct electrochemical reduction of ZrSiO4 and SiO2 in one step.
Specific heat of metastable Zr<sub>1-x</sub>Si<sub>x</sub>alloys
作者:G Flinspach、C Surgers、H von Lohneysen
DOI:10.1088/0953-8984/2/20/002
日期:1990.5.21
Non-equilibrium phases in the system Zr1-xSix prepared by liquid quenching are superconducting with intermediate electron-phonon coupling as determined from specificheat, low-field DC magnetisation and electrical resistance measurements. Analysis of the authors data clearly shows that amorphous samples (0.12
通过液体淬火制备的 Zr1-xSix 系统中的非平衡相是超导的,具有中间电子-声子耦合,根据比热、低场 DC 磁化和电阻测量确定。作者数据的分析清楚地表明,无定形样品 (0.12