Nanostructured Materials最新文献_第10页

A nanocrystalline fcc phase via devitrification of a Ni36Fe32Ta7Si8B17 amorphous alloy Ni36Fe32Ta7Si8B17非晶合金反硝化制备纳米晶fcc相

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00363-3

P Rizzi , M Baricco , G Riontino , L Battezzati

引用次数: 3

Hysteretic magnetisation curves in the granular Cu100-xCox system Cu100-xCox颗粒体系的磁滞曲线

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00364-5

P Allia , M Coisson , P Tiberto , F Vinai

引用次数: 4

Magnetic behaviour during the first crystallisation stages in Co-B amorphous alloys: a test of the exchange penetration through interfaces Co-B非晶合金第一次结晶阶段的磁性行为:通过界面交换渗透的测试

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00367-0

A Hernando , A González , C Ballesteros , A Zern , D Fiorani , F Lucari , F D’Orazio

引用次数: 3

Nitrogen sorption tests, SEM-windowless EDS and XRD analysis of mechanically alloyed nanocrystalline getter materials 机械合金化纳米晶吸气剂材料的氮吸附试验、sem -无窗EDS和XRD分析

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00372-4

G. Valdrè , D. Zacchini , R. Berti , A. Costa , A. Alessandrini , P. Zucchetti , U. Valdrè

{"title":"Nitrogen sorption tests, SEM-windowless EDS and XRD analysis of mechanically alloyed nanocrystalline getter materials","authors":"G. Valdrè , D. Zacchini , R. Berti , A. Costa , A. Alessandrini , P. Zucchetti , U. Valdrè","doi":"10.1016/S0965-9773(99)00372-4","DOIUrl":"10.1016/S0965-9773(99)00372-4","url":null,"abstract":"<div>Gas absorbing materials (getters) find several applications in modern vacuum technology; in particular to maintain required vacuum levels in evacuated and sealed enclosures. The gas absorbing properties of these getters depend on the physico-chemical nature of their surfaces. The aim of this work is to study the absorption properties of commercial Zr-based alloys (non-evaporable getters) after mechanical alloying by means of a high vacuum planetary ball milling equipped with an in-situ compaction facility. The main aim was to refine the grain size and to develop particular defect structures to enhance the getter properties. The results have shown an improvement of the specific pumping speed of the ball milled commercial Zr-Zr(V,Fe)2 alloy with respect to the starting microcrystalline material. In particular, under our experimental conditions, the specific pumping speed vs absorbed gas curve presents a maximum after 2 hours of milling; prolonged milling reduced the pumping speed of the alloyed material. This behaviour is explained in terms of two opposing simultaneous chemical and structural effects.</div>","PeriodicalId":18878,"journal":{"name":"Nanostructured Materials","volume":"11 6","pages":"Pages 821-829"},"PeriodicalIF":0.0,"publicationDate":"1999-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0965-9773(99)00372-4","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87496345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 21

Structural, mechanical and magnetic properties of nanostructured FeAl alloys during disordering and thermal recovery 纳米FeAl合金在无序和热恢复过程中的结构、力学和磁性能

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00357-8

X. Amils , J. Nogués , S. Suriñach , J.S. Muñoz , L. Lutterotti , S. Gialanella , M.D. Baró

引用次数: 25

Transmission electron microscopy investigation of SnO2 thin films for sensor devices 传感器用SnO2薄膜的透射电镜研究

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00371-2

A.M Serventi , D.G Rickerby , M.C Horrillo , R.G Saint-Jacques , J Gutiérrez

引用次数: 12

Microstructure and magnetic properties of iron-aluminum multilayers 铁铝多层膜的微观结构和磁性能

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00366-9

M Carbucicchio , C Grazzi , M Rateo , G Ruggiero , G Turilli

引用次数: 5

Study of the phase separation in amorphous silicon oxycarbide glasses under heat treatment 热处理下非晶碳化硅玻璃的相分离研究

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00360-8

H. Brequel , J. Parmentier , G.D. Sorar , L. Schiffini , S. Enzo

{"title":"Study of the phase separation in amorphous silicon oxycarbide glasses under heat treatment","authors":"H. Brequel , J. Parmentier , G.D. Sorar , L. Schiffini , S. Enzo","doi":"10.1016/S0965-9773(99)00360-8","DOIUrl":"10.1016/S0965-9773(99)00360-8","url":null,"abstract":"<div>The structural evolution of three silicon oxycarbide glasses was studied by X-ray diffraction (XRD) as a function of the pyrolysis temperature. Three compositions were prepared by the sol-gel method and pyrolysed at 1000°C under atmosphere of Ar. The black glasses obtained correspond respectively to i) silicon oxycarbide network with excess of C, ii) stoichiometric SiCxO2(1-x) where x = 0.3, and iii) silicon oxycarbide network with deficiency of C, i.e. with excess of Si. At this stage of the treatment, the samples are made up of a single and amorphous phase. A phase separation occurs after further pyrolysis in the high temperature range 1200–1500°C, leading to the formation of nanocrystalline β-SiC and amorphous SiO2. We used a cubic silica structure factor to model the component due to amorphous silica. This enabled us to apply the Rietveld method to all patterns and to obtain a satisfactory fit of the experimental data. From these refinements, the amount of each phase (crystalline or amorphous) can be determined, based on the assumption that the electron density of the model agrees with the actual amorphous phase. A comparison is also made with results from chemical analysis and 29Si Magic Angle Spinning NMR found in the litterature. Concerning the crystalline component β-SiC, its average crystallite size and microstrain were also evaluated. The evolution of the phase separation was then reported versus the pyrolysis temperature and seems to suggest a nucleation-and-growth mechanism.</div>","PeriodicalId":18878,"journal":{"name":"Nanostructured Materials","volume":"11 6","pages":"Pages 721-731"},"PeriodicalIF":0.0,"publicationDate":"1999-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0965-9773(99)00360-8","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75757311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 46

Metastable phase nucleation in irradiated metallic alloys 辐照金属合金的亚稳相成核

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00362-1

Paolo M. Ossi , Rosanna Pastorelli

引用次数: 2

Mechanical behaviour of nanocrystalline iron and nickel in the quasi-static and low frequency anelastic regime 纳米晶铁和镍在准静态和低频非弹性状态下的力学行为

Nanostructured Materials Pub Date : 1999-09-01 Epub Date: 2000-01-20 DOI: 10.1016/S0965-9773(99)00359-1

E. Bonetti , E.G. Campari , L. Del Bianco , L. Pasquini , E. Sampaolesi

{"title":"Mechanical behaviour of nanocrystalline iron and nickel in the quasi-static and low frequency anelastic regime","authors":"E. Bonetti , E.G. Campari , L. Del Bianco , L. Pasquini , E. Sampaolesi","doi":"10.1016/S0965-9773(99)00359-1","DOIUrl":"10.1016/S0965-9773(99)00359-1","url":null,"abstract":"<div>In this research, we made use of mechanical spectroscopy to study the anelastic behaviour of nanocrystalline Fe and Ni in quasi-static, low-frequency (0.01–10 Hz) regime. The elastic energy dissipation coefficient (Q−1) and the stress relaxation have been measured as a function of frequency and temperature, in a range of temperatures where appreciable grain growth is not expected to occur. The use of such low frequency probes puts into evidence a very strong change in the material response, induced by low temperature annealing (T < 200 °C). In spite of the fact that the grain size was nearly the same after the annealing treatment, the as-prepared samples displayed much higher Q−1 values and faster rates of stress relaxation than the annealed samples. The anelastic spectrum of annealed specimens has been analysed by a combination of quasi-static and dynamic measurements. The results of this study are discussed in terms of typical activation energies reported for lattice and grain boundary diffusion in coarse-grained polycrystalline and nanocrystalline metals.</div>","PeriodicalId":18878,"journal":{"name":"Nanostructured Materials","volume":"11 6","pages":"Pages 709-720"},"PeriodicalIF":0.0,"publicationDate":"1999-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/S0965-9773(99)00359-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85903531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 24