Amorphization of Crystalline Phase Change Material by Ion Implantation

2010 ◽  
Vol 1251 ◽  
Author(s):  
Simone Raoux ◽  
Guy Cohen ◽  
Robert M. Shelby ◽  
Huai-Yu Cheng ◽  
Jean L Jordan-Sweet
Keyword(s):  
Ion Implantation ◽  
Phase Change ◽  
Phase Change Material ◽  
Crystalline Phase ◽  
High Dose ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Change Material ◽  
Ion Implanted

AbstractGermanium ion implantation at an energy of 30 keV was used as a different method to re-amorphize thin films of crystalline phase change material Ge2Sb2Te5 (GST). It was found that rather low doses of 5×1013 cm-2 were sufficient to re-amorphize GST. Amorphization was determined by X-ray diffraction (XRD) as well as reflectivity measurements. Re-crystallization characteristics of ion-implantation-amorphized samples was studied using time-resolved XRD. It showed that samples re-crystallize at an increased crystallization temperature with increasing dose compared to as-deposited material. A static laser tester was applied to measure the crystallization times of material that was (1) as–deposited amorphous; (2) crystallized by annealing and re-amorphized by melt-quenching using a laser pulse; and (3) crystallized by annealing and re-amorphized by ion implantation. It was found that as-deposited amorphous and high-dose ion implanted samples had longer crystallization times while melt-quenched amorphous and low-dose ion implanted samples had shorter crystallization times.

Preparation and Properties of Polyalcohol Phase Change Material for Insulation

2012 ◽  
Vol 512-515 ◽  
pp. 936-939 ◽  
Author(s):  
Wei Wu ◽  
Yu Feng Chen ◽  
Xing Shi ◽  
Shi Chao Zhang ◽  
Hao Ran Sun
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Phase Change Materials ◽  
Heat Insulation ◽  
X Ray Diffraction ◽  
Test Device ◽  
X Ray ◽  
Composite Phase Change Materials ◽  
Change Material ◽  
Properties Of Composites

In this paper, the composite phase change materials for insulation were prepared by melt-soaking method. Trimethylolethane (PG) was chosen to be the phase change material (PCM) and two kinds of porous materials as the supporting matrices separately. The effects of both matrices to PG were analyzed by X-ray diffraction (XRD), and the heat insulation properties of composites were evaluated by Plat heat insulation test device. At last, microstructures of composites were observed by scanning electron microscope (SEM) and their effects to composites were discussed.

Study of crystalline structure N-doped GeSb Phase Change Material for PCRAM applications

2010 ◽  
Vol 1251 ◽  
Author(s):  
Audrey Bastard ◽  
Sandrine Lhostis ◽  
Caroline Bonafos ◽  
Sylvie Schamm-Chardon ◽  
Pierre-Eugène Coulon ◽  
...  
Keyword(s):  
Grain Size ◽  
Phase Change ◽  
Nitrogen Content ◽  
Phase Change Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Two Phases ◽  
Scherrer Formula ◽  
Change Material ◽  
Xrd And Tem

Abstract100 nm-thick GeSbN films with high Sb content were investigated by XRD and TEM in order to investigate crystalline phases. We observe the crystallization of the two phases separatly. First, Sb rhomboedral crystallizes at 250°C and then cubic Ge appears at 340°C according to Reflectivity and X-Ray Diffraction measurements. With the incorporation of nitrogen in the thick films, a delay to crystallization of the two phases is observed. Grain size measurements with Scherrer formula support the decrease of grain crystallization with N content. Moreover, TEM observations show clearly the separation of the two phases in the layer and the reduction in size of the grains with nitrogen content. This allows a better re-amorphization than films without nitrogen.

Crystallization Characteristics Of Phase Change Nanoparticle Arrays Fabricated By Self-Assembly Based Lithography

2008 ◽  
Vol 1072 ◽  
Author(s):  
Yuan Zhang ◽  
Simone Raoux ◽  
Daniel Krebs ◽  
Leslie E. Krupp ◽  
Teya Topuria ◽  
...  
Keyword(s):  
Phase Change ◽  
Self Assembly ◽  
Crystallization Behavior ◽  
Small Scale ◽  
Nanoparticle Arrays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Nanodot Arrays ◽  
Patterned Materials

ABSTRACTPhase change nanodot arrays were fabricated using self-assembly diblock copolymer template PS-b-PMMA (polystyrene-poly (methyl-methacrylate)) and studied by time resolved X-ray diffraction. The size of the nanodots was less than 15nm in diameter with 40nm spacing. This method is quite flexible regarding the patterned materials, and can be used on different substrates. The crystallization behavior of small scale phase change nanodot arrays was studied for different materials, such as Ge15Sb85, Ge2Sb2Te5 and Ag and In doped Sb2Te. It was found that the nanodots had higher crystallization temperatures compared to their corresponding blanket films and crystallized over a broader temperature range.

Ion Implantation of Ti,Mo W,Mo+C and W+C in H13 Steel and Aluminum at Elevated Temperature

1993 ◽  
Vol 316 ◽  
Author(s):  
Zhang Tonghe ◽  
Wei Fuzhong ◽  
Chen Jun ◽  
Zhang huixing ◽  
Zhang Xioji ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Peak Concentration ◽  
Chemical Change ◽  
High Dose ◽  
Second Phase ◽  
Target Temperature ◽  
X Ray Diffraction ◽  
H13 Steel ◽  
X Ray ◽  
Second Phases

ABSTRACTThe chemical change in the surface of H13 steel or aluminum is produced by implanting a reactive elements, such as Ti, Mo and W. The X-ray diffraction pattern shows that implanted Ti at 400 C has reacted with carbon(0.35 in wt.%) forming a second phase TiC. Auger analysis shows that the carbon atoms have been condensed in the Ti implanted region. Carbon peak concentration of 30 At.% is greater than Ti atom peak concentration of 12 At.%.Several second phases are formed during pulsed Mo ion implantation 2 into aluminum with high ion flux of 50˜80µA/cm2 which raises the target temperature from 400°C to 600°C.More second phases are formed by dual Mo+C implantation with high dose of 3˜5×10 17/cm2 and high flux of 50˜75µA/cm2 . And the target temperature is raised from 400 to 600°C. The FeMo Fe3Mo2, Fe2MoC, Mo2C, MoC, MoCx, phases and iron carbides are identified by X-ray diffraction technique.

D085 Synchrotron X-ray Study of Structural Phase Transformations in Continuous and Patterned Ge2Sb2Te5 Phase-Change Material Thin Films

2005 ◽  
Vol 20 (2) ◽  
pp. 174-174
Author(s):  
J.L. Jordan-Sweet ◽  
S.M. Rossnagel ◽  
P.M. Mooney ◽  
S. Raoux ◽  
C.T. Rettner
Keyword(s):  
Thin Films ◽  
Phase Change ◽  
Phase Transformations ◽  
Phase Change Material ◽  
Structural Phase ◽  
X Ray ◽  
Change Material ◽  
Structural Phase Transformations

Crystallization Characteristics of Ge-Sb Phase Change Materials

2009 ◽  
Vol 1160 ◽  
Author(s):  
Simone Raoux ◽  
Cyril Cabral ◽  
Lia Krusin-Elbaum ◽  
Jean L. Jordan-Sweet ◽  
Martin Salinga ◽  
...  
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Mass Density ◽  
Large Change ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Time Resolved ◽  
X Ray ◽  
Diffraction Peaks ◽  
Low X

AbstractThe crystallization behavior of Ge-Sb phase change materials with variable Ge:Sb ratio X between 0.079 and 4.3 was studied using time-resolved x-ray diffraction, differential scanning calorimetry, x-ray reflectivity, optical reflectivity and resistivity vs. temperature measurements. It was found that the crystallization temperature increases with Ge content from about 130 °C for X = 0.079 to about 450 °C for X = 4.3. For low X, Sb x-ray diffraction peaks occurred during a heating ramp at lower temperature than Ge diffraction peaks. For X = 1.44 and higher, Sb and Ge peaks occurred at the same temperature. Mass density change upon crystallization and optical and electrical contrast between the phases show a maximum for the eutectic alloy with X = 0.17. The large change in materials properties with composition allows tailoring of the crystallization properties for specific application requirements.

Time-Resolved X-Ray Diffraction Study on Solidification of Fe-B and Fe-C Eutectic Alloys

2012 ◽  
Vol 706-709 ◽  
pp. 1702-1706 ◽  
Author(s):  
Akitoshi Mizuno ◽  
Jin Tamura ◽  
Shinji Kohara ◽  
Masahito Watanabe
Keyword(s):  
Cooling Rate ◽  
Crystalline Phase ◽  
Metastable Phase ◽  
Transformation Process ◽  
Undercooled Liquid ◽  
Eutectic Alloys ◽  
X Ray Diffraction ◽  
Structural Variations ◽  
Time Resolved ◽  
X Ray

Solidification processes of Fe-B and Fe-C eutectic alloys have been investigated by a time-resolved synchrotron x-ray diffraction under containerless cooling conditions using a conical nozzle levitation technique. To observe relative variations of structure from the undercooled liquid to crystalline phase, we have conducted millisecond order time-resolved x-ray diffraction experiments with a two-dimensional detector. The structural variations observed during the solidification of the Fe83C17alloy were identified as the phase transformation process expected from the Fe-C phase diagram. As for the Fe83B17alloy, it was revealed that a metastable phase composed of Fe23B6compound was precipitated as a primary crystalline phase from the undercooled liquid. In addition, decomposition of the metastable Fe23B6phase showed dependence on the cooling rate of the sample. At the cooling rate of 30 K/s, the Fe23B6phase decomposed to bcc-Fe and Fe2B phases with decreasing temperature. On the contrary, at the cooling rate of 180 K/s, the metastable Fe23B6phase remained in spite of an appearance of the bcc-Fe phase. By comparing the primary crystalline phase between the Fe83C17and the Fe83B17alloys, we suggest that the formability of the metastable Cr23C6-type compound is closely related with the glass-forming ability of Fe-metalloid binary alloys.

Myristic Acid/Montmorillonite Composite as Shape Stabilized Phase Change Material for Thermal Energy Storage

2011 ◽  
Vol 332-334 ◽  
pp. 935-938
Author(s):  
Zhong Li ◽  
Shao Ming Yu ◽  
De Xin Tan ◽  
Tong He Yao
Keyword(s):  
Phase Change ◽  
Phase Change Material ◽  
Myristic Acid ◽  
Xrd Analysis ◽  
High Heat ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Analysis Technique ◽  
New Type ◽  
Change Material

A new type of shape stabilized phase change material (PCM) with good heat storage was produced by intercalating myristic acid (MA) with modifid montmorillonite (MMT). The structure, thermal properties of the composite PCM were determined by X-ray diffraction (XRD), Fourier transformation infrared (FTIR) and Differential Scanning Calorimetry (DSC) analysis technique. In the XRD analysis, expansions of the d spacings in the (001) plane were observed in all samples, indicating that the intercalation of MA in the interlayers of MMT was successfully achieved. The results of DSC indicated that the shape stabilized PCM displayed a high heat capacity (133.6 J.g-1)

Exafs Studies of Cobalt Silicide Formation Produced by High Dose Ion Implantation

1988 ◽  
Vol 143 ◽  
Author(s):  
Z. Tan ◽  
J. I. Budnick ◽  
F. Sanchez ◽  
G. Tourillon ◽  
F. Namavar ◽  
...  
Keyword(s):  
Fine Structure ◽  
Ion Implantation ◽  
Single Phase ◽  
High Dose ◽  
Cobalt Silicide ◽  
Silicide Formation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ordered Phases ◽  
X Ray Absorption

AbstractThe early stages of cobalt silicide formation in high dose (1.0 to 8.0× 1017Co/cm2) cobalt implanted Si(100) are studied by extended X-ray absorption fine structure (EXAFS), X-ray diffraction (XRD) and Rutherford backscattering spectroscopy (RBS). Locally ordered silicide that is not detectable in XRD has been observed with EXAFS in the as-implanted samples. Long-range ordered phases are observed in the 3 × 1017Co/cm2 samples. After thermal annealing at 700–750°C, single phase CoSi2 with (400) orientation is formed in all implants.

Direct observation of structural transitions in the phase change material Ge2Sb2Te5

2016 ◽  
Vol 4 (39) ◽  
pp. 9303-9309 ◽  
Author(s):  
Ruiwen Shao ◽  
Kun Zheng ◽  
Yongjin Chen ◽  
Bin Zhang ◽  
Qingsong Deng ◽  
...  
Keyword(s):  
Electric Field ◽  
Phase Change ◽  
Phase Change Material ◽  
Direct Observation ◽  
Crystalline Phase ◽  
Structural Transitions ◽  
Single Crystalline ◽  
Multi Level ◽  
Change Material

Electric field-induced transitions from an amorphous to a polycrystalline to a single-crystalline phase in Ge2Sb2Te5were observed, which corresponded to multi-level changes in resistance.

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