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Influence of Target-Substrate Distance and Sputtering Power on chromium oxide Films Prepared by Medium-Frequency Magnetron Sputtering

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Wuhan University Journal of Natural Sciences 2010年第5期15卷 440-443页

作者： YANG Huijuan,HE Jun,TIAN Canxin,LIU Chuansheng,FU Dejun School of Physics and Technology,Wuhan University,Wuhan 430072,Hubei,China School of Physics and Technology Wuhan University Wuhan Hubei China

chromium oxide films were deposited on Si（100） substrates by medium-frequency（MF） unbalanced magnetron sputtering at different target-substrate distances DTS（60,100,120 mm） and sputtering power（2.8,5.6,11.2 kW）,*** structure,surface morphologies,and microhardness of the chromium oxide films were examined by X-ray diffraction（XRD）,atomic force microscopy（AFM）,and microhardness *** results indicate that elevated MF sputtering power can improve the crystallization of the films;The DTS value affects the structure of the films by changing the preferential orientation from CrO3（221） to Cr2O3（116）;The microhardness of the chromium oxide films is found to increase with the sputtering *** preparing the Cr2O3-dominated films with comparatively high-performance,the optimized condition is the target-substrate distance of 100 mm and MF sputtering power of 11.2 kW.

关键词： chromium oxide magnetron sputtering microstruc-ture hardness

Use of chromium oxide and Alkane Indicator Methods for Determination of Feed Intake for Grazing Sheep

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Journal of Agricultural Science and Technology(A) 2017年第3期7卷 199-208页

作者： Selcuk Altacli Suphi Deniz Department of Animal Nutrition and Nutritional Diseases Faculty of Veterinary Medicine University of Yuzuncu Yil Van 65080 Turkey

This experiment was carried out to determine feed intake and digestibility of grazing sheep on pasture. A total of 14 animals randomly divided into two groups with seven animals each group were used in the experiment. Digestibility of pastures was determined using two types of markers-alkane （C32-C36） and chromium oxide. Dry matter intake （DMI） was 717.22 g/d based on chromium oxide method in the experiment, while according to alkane method, DMI was 965.93 g/d and 1,051.07 g/d for C32 and C36, respectively. In conclusion, pastures met 74%-81% of crude protein （CP） and 57%-61% of energy requirements of lambs grazing on Yuzuncu Yil University pasture, who are mid-quality and 4-7 month-old with a 275 g/d expected daily gain. It was calculated that when 628-693 g/d of barley is given, both CP and metabolizable energy （ME） requirements of animals can be met.

关键词： Pasture chromium oxide alkane feed intake digestibility energy content.

Preparation of chromium oxide Coatings on Aluminum Borate Whiskers by a Hydrothermal Deposition Process

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Tsinghua Science and Technology 2002年第1期7卷 78-81,90页

作者：向兰 Department of Chemical Engineering Tsinghua University Beijing 100084 China Shikoku National Industrial Research Institute 2217-14 Hayashi-cho Takamatsu 761-03 Japan

Aluminum borate whiskers (9Al 2O 3·2B 2O 3) can be used to reinforce aluminum alloys to produce light and strong composites. However, the adverse interfacial reactions between the whiskers and the aluminum alloys inhibit their practical uses; therefore, a protective coating is needed on whiskers. In this work, aluminum borate whiskers were coated with chromium coating deposits in a hydrothermal solution containing CrCl 3, Na 2C 4H 4O 6, NaPH 2O 2, and H 3BO 3. The presence of the impurity P in the hydrothermal deposits can be avoided by reducing the amount of NaPH 2O 2 in the coating solution. Thermodynamic analysis was used to discuss the behavior of ions in the coating process. The subsequent heating of the hydrothermal products in air at 800 ℃ yielded smooth Cr 2O 3 films with a thickness of 0.060.07 μm. 

关键词： aluminum borate whiskers chromium oxide hydrothermal deposition coating films

Direct electrolytic preparation of chromium metal in CaCl_2-NaCl eutectic salt

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Transactions of Nonferrous Metals Society of China 2018年第2期28卷 376-384页

作者：刘政伟张红玲裴丽丽石义朗蔡再华徐红彬张懿中国科学院绿色过程与工程重点实验室(中国科学院过程研究所) 北京100190 中国科学院过程工程研究所湿法冶金清洁生产技术国家工程实验室北京100190 中国科学院大学北京100049 湖北振华化学股份有限公司黄石435001

The electro-reduction of chromium oxide（Cr2O3） was investigated in an equimolar mixture of CaCl2-NaCl molten salt at 800℃ for developing a more efficient process for chromium preparation. Cyclic voltammetry and potentiostatic electrolysis were used to study the electro-reduction of the Cr2O3-loaded metallic cavity electrode. In addition, a number of parameters affecting the rate and extent of Cr2O3 electrolysis were considered to better understand the electrolysis process. The results demonstrate that CaCl2-NaCl molten salt is applicable for preparing Cr directly from Cr2O3 and the electrolysis parameters exert great influence on the cathode product. Under optimal experimental conditions, nodular Cr with an oxygen content of 0.5%（mass fraction） was obtained without any chromium carbides detected by XRD. Furthermore, the relatively high solubility of CaO and quite rapid crystal growth result in the formation of large platelet CaCr2O4, and the addition of NaCl to CaCl2 results in several variations on the electrolysis process and the product morphology from pure CaCl2 molten salt.

关键词： electrolysis chromium chromium oxide CaCl2-NaCl molten salt

A novel lithium-ion battery comprising Li-rich@Cr_2O_5composite cathode and Li_4Ti_5O_(12) anode with controllable coulombic efficiency

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Science China Materials 2017年第9期60卷 839-848页

作者：丁翔邹邦坤李禹宣贺晓东廖家英唐仲丰邵宇陈春华 CAS Key Laboratory of Materials for Energy Conversions Department of Materials Science and Engineering&Collaborative Innovation Center ofSuzhou Nano Science and TechnologyUniversity of Science and Technology of China

Through meticulous design, a Li-lacking Cr2O5 cathode is physically mixed with Li-rich Li（1.2）Ni（0.13）Co（0.13）Mn（0.54）O2（LNCM） cathode to form composite cathodes LNCM@x Cr2O5（x = 0, 0.1, 0.2, 0.3, 0.35, 0.4, mass ratio） in order to make use of the excess lithium produced by the Li-rich component in the first charge-discharge process. The initial coulombic efficiency（ICE） of LNCM half-cell has been significantly increased from75.5%（x = 0） to 108.9%（x = 0.35）. A novel full-cell comprising LNCM@Cr2O5composite cathode and Li4Ti5O（12） anode has been developed. Such electrode accordance, i.e., LNCM@Cr2O5//Li4Ti5O（12）（＂L-cell＂）, shows a particularly high ICE of97.7%. The ＂L-cell＂ can transmit an outstanding reversible capacity up to 250 mA h g-1and has 94% capacity retention during 50 cycles. It also has superior rate capacities as high as122 and 94 mA h g-（-1）at 1.25 and 2.5 A g-（-1）current densities,which are even better in comparison of Li-rich//graphite fullcell（＂G-cell＂）. The high performance of ＂L-cell＂ benefiting from the well-designed coulombic efficiency accordance mechanism displays a great potential for fast charge-discharge applications in future high-energy lithium ion batteries.

关键词： Li-rich cathode chromium oxide lithium titanium oxide electrode accordance rate capability

Effect of TiO2 on reduction behavior of Cr2O3 in CaO-SiO2-Al2O3-MgO-TiO2-Cr2O3 by carbon from Fe-C melt

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Journal of Iron and Steel Research International 2020年第10期27卷 1145-1152页

作者： Jun-yi Xiang Gui-shang Pei Wei Lv Bao-hua Li Gui-bao Qiu Xue-wei Lv College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key Laboratory of Vanadium-Titanium Metallurgy and Advanced Materials Chongqing UniversityChongqing 400044China

The chromium-bearing titanomagnetite ore will turn to be the important raw material for blast furnace process in Panxi area,*** reduction behavior of Cr2O3 between CaO-SiO2-Al2O3-TiO2-Cr2O3 and Fe-C systems was *** effect of TiO2 content in the slag system on the reduction of Cr2O3,TiO2,and SiO2 and the con sumption of C in hot metal was investigated by both theoretical calculation and physical *** theoretical calculation results reveal that higher reduction temperature promotes the reduction of Cr and Ti,while high basicity and TiO2 content have little influence on the reduction of chromium but significantly influence the reduction of *** smelting reduction experiment results show that the content of Cr in hot metal significantly in creases with extendi ng the reduction time and decreases with the increase in TiO2 ***,the content of Ti in hot metal significantly increases as the TiO2 increases,reaching 0.073,0.085,0.107,and 0.121 wt.%for 5,10,15,and 20 wt.%of TiO2 input,*** studies proved that the reduction of Cr2O3 was a first-order *** addition of TiO2 inhibited the reduction of Cr2O3 and resulted in the decrease in reaction rate constant.

关键词： Smelting reduction Titanomagnetite Blast furnace slag chromium oxide Titanium oxide

CrOx supported on high-silica HZSM-5 for propane dehydrogenation

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Journal of Energy Chemistry 2020年第8期29卷 225-233,I0008页

作者： Zhong-Pan Hu Yansu Wang Dandan Yang Zhong-Yong Yuan National Institute for Advanced Materials School of Materials Science and EngineeringNankai UniversityTianjin 300350China Key Laboratory of Advanced Energy Materials Chemistry(Ministry of Education).Nankai University Tianjin 300071China

Industrial propane dehydrogenation(PDH)catalysts generally suffer from low catalytic stability due to the coke formation onto the catalyst surface to cover the active *** exploitation of an efficient catalyst with both high catalytic selectivity and long-term stability toward PDH is of great importance but challenging to *** CrOx supported on high-silica HZSM-5 with a SiO2/Al2O3 ratio of 260(Cr/Z-5(260)is synthesized by a simple wet impregnation method,which exhibits high catalytic activity,good selectivity and excellent stability for *** a weight hourly space velocity(WHSV)of 0.59 h-1,a propylene formation rate of 4.1 mmol g-1cath-1(~32.6% propane conversion and ~94.2% propylene selectivity)can be maintained over the 5%Cr/Z-5(260)catalyst after 50 h time on stream,which is much better than commercial Cr/Al2O3(Catofin process,catalyst life is several hours)at the same reaction *** increasing the WHSV to 5.9 h-1,a high propylene formation rate of 27.9 mmol gcat-1h-1can be obtained over the 5%Cr/Z-5(260)catalyst after 50 h time on stream,demonstrating a very promising PDH *** results and Na+doping experiments reveal that the Cr species combined with Br?nsted acid sites in Cr/HZSM-5 catalysts are responsible for the high catalytic *** particular,the Br?nsted acid sites in HZSM-5 zeolite could increase the propane adsorption and enhance the C–H bond ***,the high surface area and well-defined pores of HZSM-5 zeolite can provide a special environment for the dispersion and stabilization of Cr species,thus guaranteeing high catalytic activity and stability.

关键词： Propane dehydrogenation ZSM-5 zeolite chromium oxide Propylene BrΦnsted acid sites

Preparation of hexagonal and amorphous chromium oxyhydroxides by facile hydrolysis of K_xCrO_y

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Transactions of Nonferrous Metals Society of China 2020年第5期30卷 1397-1405页

作者： Shu-ting LIANG Hong-ling ZHANG Hong-bin XU College of Chemistry and Environmental Engineering Chongqing University of Arts and SciencesChongqing 402160China Chongqing Key Laboratory of Environmental Materials and Remediation Technologies Chongqing University of Arts and SciencesChongqing 402160China National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process EngineeringChinese Academy of ScienceBeijing 100190China Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China

The hydrolysis process and mechanisms of unique as-prepared KCrO2 and K3 CrO4 were systematically investigated. The characterization results of XRD, IR and SEM show that the hydrolysis reaction can be realized at a low reaction temperature of 80 ℃ and a reaction time of 24 h. Moreover, the greyish-green α-CrOOH with a hexagonal plate-like morphology and a large size of 10 μm is formed via the hydrolysis of the single-phase hexagonal KCrO2, while the green sol-gel of amorphous Cr(OH)3 with a lumpy aggregate morphology is generated through the hydrolysis of a cubic K3 CrO4. It is a facile and rapid method to synthesize pure-phase chromium oxyhydroxide via the above hydrolysis.

关键词： hydrolysis process CrOOH chromium oxide activated KxCrOy reaction mechanism

Effects of lanthanum ion-implantation on microstructure of oxide film formed on Co-Cr alloy

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Journal of Rare Earths 2008年第3期26卷 406-409页

作者：靳惠明周小卫张林楠 Materials Research Center College of Mechanical Engineering Yangzhou University College of Environmental Science and Engineering Peking University

Isothermal and cyclic oxidizing behavior of Co-40Cr alloy and its lanthanum ion-implanted samples were studied at 1000 ℃ in the air by thermal-gravimetric analysis （TGA）. Scanning electronic microscopy （SEM） and transmission electronic microscopy （TEM） were used to examine the morphology and structure of oxide film after oxidation. Secondary ion mass spectrum （SIMS） method was used to examine the binding energy change of chromium caused by La-doping and its influence on the formation of Cr2O3 film. laser Raman spectrum was used to examine the stress changes within the oxide film. It was found that lanthanum implantation remarkably reduced isothermal oxidizing rate of Co-40Cr and improved anti-cracking and anti-spalling properties of Cr2O3 oxide film. The reasons for the improvement were mainly that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide and increased high temperature plasticity of the oxide film. Lanthanum mainly existed on the outer surface of Cr2O3 oxide film in the form of fine La2O3 and LaCrO3 spinel particles.

关键词： ion implantation lanthanum chromium oxide raman spectrum SIMS rare earths