A novel bioactive glass containing strontium and magnesium with ultra-high crystallization temperature

2018 ◽  
Vol 213 ◽  
pp. 67-70 ◽  
Author(s):  
Devis Bellucci ◽  
Valeria Cannillo
Keyword(s):  
Bioactive Glass ◽  
Crystallization Temperature ◽  
High Crystallization ◽  
High Crystallization Temperature

scholarly journals A Novel Bioactive Glass Containing Therapeutic Ions with Enhanced Biocompatibility

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4600 ◽  
Author(s):  
Rachele Sergi ◽  
Devis Bellucci ◽  
Roberta Salvatori ◽  
Alexandre Anesi ◽  
Valeria Cannillo
Keyword(s):  
Bioactive Glass ◽  
Dissolution Rate ◽  
Crystallization Temperature ◽  
Biological Properties ◽  
Thermal Treatments ◽  
Cellular Viability ◽  
In Vitro Bioactivity ◽  
High Crystallization ◽  
High Crystallization Temperature

A novel bioactive glass containing therapeutic ions with enhanced biocompatibility was designed and produced by the classical melt-quenching route. Starting from a very promising composition (Bio_MS), which combined bioactivity and high crystallization temperature, the ratio between some oxides was tailored to obtain a new and more reactive (in terms of dissolution rate) bioactive glass, called BGMSN (composition in mol%: 6.1 Na2O, 31.3 CaO, 5 MgO, 10 SrO, 2.6 P2O5, 45 SiO2). The aim of this work was to produce a bioactive glass with a good biological performance, preserving, at the same time, the high crystallization temperature achieved for Bio_MS; this is strategic in order to avoid undesired crystalline phases during thermal treatments, which can undermine the bioactivity and even the stability of final products. A complete characterization of the novel bioactive glass was performed in terms of thermal, mechanical and biological properties and in vitro bioactivity. The thermal behavior of the bioactive glass was studied by heating microscopy, differential thermal analysis (DTA) and optical dilatometry; BGMSN showed a very high crystallization temperature and a high sinterability parameter, thus being suitable for applications where thermal treatments are required, such as sintered samples, coatings and scaffolds. Mechanical properties were investigated by the micro-indentation technique. The in vitro biological properties were evaluated by means of both direct and indirect cell tests, i.e., neutral red (NR) uptake and MTT assay, using murine long bone osteocyte Y4 (MLO-Y4) cells: the cellular viability of BGMSN was higher compared to cellular viability of 45S5, both in direct and indirect tests. Finally, the in vitro bioactivity test by soaking samples in simulated body fluid (SBF) showed high dissolution rate, with a good rate of formation of hydroxyapatite.

Evaluation of Mo-based Amorphous Alloy Thin Films Exhibiting High Crystallization Temperature

2005 ◽  
Vol 894 ◽  
Author(s):  
Junpei Sakurai ◽  
Seiichi Hata ◽  
Ryusuke Yamauchi ◽  
Akira Shimokohbe
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Amorphous Alloy ◽  
Crystallization Temperature ◽  
Alloy Composition ◽  
Phase Distribution ◽  
Amorphous State ◽  
Al Alloy ◽  
High Crystallization ◽  
High Crystallization Temperature

AbstractThis paper presents the characteristics of Mo-based (Mo-Zr based) amorphous alloys exhibiting a high crystallization temperature. In order to investigate the alloy composition showing an amorphous state in the Mo-Zr-X (X=Si and Al) alloy system, thin film libraries were prepared at first by combinatorial arc plasma deposition (CAPD). The composition region corresponding to the amorphous state was identified in the libraries with X-ray diffraction. On the basis of the alloy composition and phase distribution of the thin film libraries, additional amorphous Mo-Zr-Si and Mo-Zr-Al thin films were prepared by a carousel sputtering system. The crystallization temperature Tc of the amorphous Mo50Zr(50-x)Six thin films exceeded 1073 K. However, the Mo-Zr-Si thin films were so brittle that they could not be subjected to tensile testing. In the Mo-Zr-Al thin films, Tc of the Mo-rich MoxZr(90-x)Al10 and MoxZr(76-x)Al24 thin films exceeded 973 K. Although the toughness of Mo-based amorphous alloy thin films could be improved slightly by adding Al, the amorphous Mo-Zr-Al thin films were also brittle.

Improved electrical and material characteristics of HfTaO gate dielectrics with high crystallization temperature

2005 ◽  
Vol 87 (23) ◽  
pp. 232901 ◽  
Author(s):  
M. H. Zhang ◽  
S. J. Rhee ◽  
C. Y. Kang ◽  
C. H. Choi ◽  
M. S. Akbar ◽  
...  
Keyword(s):  
Crystallization Temperature ◽  
Gate Dielectrics ◽  
Material Characteristics ◽  
High Crystallization ◽  
High Crystallization Temperature

scholarly journals Effects of different sintering temperatures on thermal, physical, and morphological of SiO2-Na2O-CaO-P2O5 based glass-ceramic system from vitreous and ceramic wastes

2019 ◽  
Vol 51 (4) ◽  
pp. 377-387
Author(s):  
Nur Pallan ◽  
Khamirul Matori ◽  
Mansor Hashim ◽  
Raba’ah Azis ◽  
Norhazlin Zainuddin ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Sintering Temperature ◽  
Soda Lime ◽  
Sample Thickness ◽  
Morphological Properties ◽  
Ceramic System ◽  
Melt Quenching ◽  
Solid State Sintering ◽  
High Crystallization ◽  
High Crystallization Temperature

This research involved comprehensive studies on thermal, physical, and morphological properties of SiO2-Na2O-CaO-P2O5 (SNCP) glass-ceramic at various sintering temperatures. The study in SNCP glass-ceramic using soda-lime-silica (SLS) wastes glass and clam shell (CS) wastes as the main raw of materials via conventional melt-quenching technique and solid state sintering are interesting and challenging by considering the research using waste materials to fabricate novel SNCP glass-ceramic. The main peaks, Na3PO4 and Ca3Na6Si6O18 were assigned to high crystallization temperature (Tc) at 650-950?C. The density of samples increases at 550-750?C and decreases at 850-950?C due to the increase of sample thickness and higher specific volume at high sintering temperature. FESEM micrograph showed that existed porous increased at sintering temperature 850-950?C contributes effect to low densification of the sample.

A Mechanically-Alloyed Amorphous 2Si-B-3C-N Ceramic with a Crystallization Temperature up to 1800°C

2018 ◽  
Vol 281 ◽  
pp. 323-329
Author(s):  
Peng Fei Zhang ◽  
De Chang Jia ◽  
Bin Yang ◽  
Guang Xin Wang
Keyword(s):  
Crystallization Temperature ◽  
Composite Powder ◽  
Hexagonal Boron Nitride ◽  
Silicon Powder ◽  
Graphite Powder ◽  
Amorphous Structure ◽  
Mechanically Alloyed ◽  
Boron Nitride Powder ◽  
Average Grain Size ◽  
High Crystallization Temperature

A mixture of cubic silicon powder, hexagonal boron nitride powder and graphite powder was mechanically alloyed for 30 hrs in argon. The as-milled 2Si-B-3C-N composite powder was heated up to 1900 °C in nitrogen, with a heating rate of 25 °C/min and under a pressure of 80 MPa. XRD and HRTEM results show that the as-milled 2Si-B-3C-N composite powder has a well amorphous structure. Under the current hot-pressing circumstances, the amorphous ceramic starts to crystallize at a temperature between 1800 °C and 1900 °C. Once the temperature is higher than crystallization temperature, crystallites appear in the amorphous matrix with a great nucleation rate, but a small growth rate. Hot pressed at 1900 °C for 0 mins or 10 mins, the prepared 2Si-B-3C-N bulk ceramic has an average grain size of 8.7 nanometers and 22.3 nanometers, respectively. After an intensive literature search, we believe the present work is the first one to make clear that it is possible to use the mechanical alloying route to prepare amorphous Si-B-C-N ceramic with such a high crystallization temperature.

The Ferroelectricity and Crystallinity of Zirconia, Hafnia and Hafnium Zirconium Oxide (HZO) Ultrathin Films Prepared by Atomic Layer Deposition With and Without Post-Annealing

2018 ◽  
Author(s):  
Tzu-Yao Hsu ◽  
Bo-Ting Lin ◽  
Jay Shieh ◽  
Miin-Jang Chen
Keyword(s):  
High Pressure ◽  
Atomic Layer Deposition ◽  
Ultrathin Films ◽  
Zirconium Oxide ◽  
Atomic Layer ◽  
Post Annealing ◽  
Layer Deposition ◽  
High Crystallization ◽  
O Phase ◽  
High Crystallization Temperature

Large stable ferroelectricity in hafnium zirconium oxide (HZO) solid solution ultrathin films (including pure zirconia (ZrO2) and hafnia (HfO2)) and ZrO2/HfO2 bilayer ultrathin films of thickness ranging from 5–12 nm, prepared by thermal atomic layer deposition or remote plasma atomic layer deposition (RP-ALD) has been demonstrated. Ferroelectric crystallization of the ZrO2 ultrathin film with high-pressure orthorhombic (o) space group Pbc21 could be achieved without post-annealing due to the plasma-induced thermal stresses experienced by the film during the RP-ALD process. In contrast, for the ZrO2/HfO2 bilayer ultrathin film, due to the high crystallization temperature of HfO2, post-annealing was needed to achieve sufficient confinement of the sandwiched HfO2 layer by the ZrO2 top layer and Si bottom substrate to promote the high-pressure ferroelectric o-phase in HfO2. The ferroelectric properties of the HZO ultrathin films prepared by RP-ALD were highly dependent on the Hf-to-Zr ratio — an increasing amount of HfO2 has been found to be detrimental to the ferroelectricity, mainly due to the high crystallization temperature of HfO2. Without post-annealing, the ferroelectricity of the HZO ultrathin films was governed by the relative amounts of the amorphous phase and the ferroelectric o-phase induced by the plasma treatment. While with post-annealing, the ferroelectricity was governed by the relative amounts of the ferroelectric o-phase and the non-ferroelectric monoclinic (m) phase.

Sign in / Sign up

Export Citation Format

Share Document