G. Mendoza-Suárez

Bio: G. Mendoza-Suárez is an academic researcher from CINVESTAV. The author has contributed to research in topics: Coercivity & Magnetization. The author has an hindex of 17, co-authored 33 publications receiving 1909 citations. Previous affiliations of G. Mendoza-Suárez include University of Sheffield & McGill University.

Wettability and spreading kinetics of molten aluminum on copper-coated ceramics

Abstract: The purpose of this study was to investigate the influence of Cu-coating on the spreading kinetics and equilibrium contact angles of aluminum on ceramics using a sessile drop technique. Al2O3 and SiC plates were coated by electroless plating. The copper film overcomes the low wetting of the uncoated samples by dissolution in the drop at 800 °C in argon, showing an intrinsically favorable effect on the adhesion energy. Just after 2 min, the contact angle decreased to 12.6° and 26°for Al/Cu–Al2O3 and Al/Cu–SiC, respectively. However, a de-wetting behavior was observed, reaching equilibrium contact angles of 58.3° and 45.5° for the couples. The dissolution reaction rate at the triple junction was so high that the spreading process was controlled by local diffusion rather than chemical reaction kinetics.

Hydration Products and Reactivity of Blast‐Furnace Slag Activated by Various Alkalis

Abstract: Pastes of blast-furnace slag were cured for up to 90 d using sodium silicate (waterglass), NaOH, and three different mixtures of Na2CO3–Na2SO4–Ca(OH)2 to activate reactions. The highest slag reactivity was observed for NaOH activation and the least for waterglass, although nonevaporable water indicated similar amounts of hydration products formed. The main hydration products found using X-ray diffractometry in all systems were calcium silicate hydrate (C-S-H) and a hydrotalcite-type phase. Microanalysis was performed on pastes activated using 50% Na2CO325% Na2SO425% Ca(OH)2, NaOH, and waterglass; the chemical composition of the C-S-H in the waterglass case was different relative to the other two alkalis. For all alkaline agents used, the C-S-H seemed finely intermixed with a hydrotalcitetype phase of Mg/Al 1.82, on average.

Magnetic properties and microstructure of BaFe11.6−2xTixMxO19 (M=Co, Zn, Sn) compounds

Abstract: BaFe11.6−2xMxTixO19 (M=Co2+, Zn2+, Sn2+) compounds in powder form were prepared by a sol–gel route. The materials were annealed at several temperatures and characterised. The results showed that the cationic substitutions (x) lowered the coercivity (Hci), presumably due to the decrease of the magnetocrystalline anisotropy of the doped Ba ferrites. Sn–Ti mixtures decreased Hci faster than Zn–Ti and Ti–Co; however, lower magnetisations were achieved. In this regard, BaMZn–Ti showed slightly higher magnetisation than BaMTi–Co compounds. The effect of the heat-treatment temperature was to increase the magnetisation, following a slight coercivity decrease due to grain coarsening.

Degradable biomaterials based on magnesium corrosion

Abstract: Biodegradable metals are breaking the current paradigm in biomaterial science to develop only corrosion resistant metals. In particular, metals which consist of trace elements existing in the human body are promising candidates for temporary implant materials. These implants would be temporarily needed to provide mechanical support during the healing process of the injured or pathological tissue. Magnesium and its alloys have been investigated recently by many authors as a suitable biodegradable biomaterial. In this investigative review we would like to summarize the latest achievements and comment on the selection and use, test methods and the approaches to develop and produce magnesium alloys that are intended to perform clinically with an appropriate host response.

Additive manufacturing: technology, applications and research needs

Abstract: Additive manufacturing (AM) technology has been researched and developed for more than 20 years. Rather than removing materials, AM processes make three-dimensional parts directly from CAD models by adding materials layer by layer, offering the beneficial ability to build parts with geometric and material complexities that could not be produced by subtractive manufacturing processes. Through intensive research over the past two decades, significant progress has been made in the development and commercialization of new and innovative AM processes, as well as numerous practical applications in aerospace, automotive, biomedical, energy and other fields. This paper reviews the main processes, materials and applications of the current AM technology and presents future research needs for this technology.

Nanocomposites: synthesis, structure, properties and new application opportunities

Abstract: Nanocomposites, a high performance material exhibit unusual property combinations and unique design possibilities. With an estimated annual growth rate of about 25% and fastest demand to be in engineering plastics and elastomers, their potential is so striking that they are useful in several areas ranging from packaging to biomedical applications. In this unified overview the three types of matrix nanocomposites are presented underlining the need for these materials, their processing methods and some recent results on structure, properties and potential applications, perspectives including need for such materials in future space mission and other interesting applications together with market and safety aspects. Possible uses of natural materials such as clay based minerals, chrysotile and lignocellulosic fibers are highlighted. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors of the aerospace, automotive, electronics and biotechnology industries.

Silicon quantum electronics

Abstract: This review describes recent groundbreaking results in Si, Si/SiGe, and dopant-based quantum dots, and it highlights the remarkable advances in Si-based quantum physics that have occurred in the past few years. This progress has been possible thanks to materials development of Si quantum devices, and the physical understanding of quantum effects in silicon. Recent critical steps include the isolation of single electrons, the observation of spin blockade, and single-shot readout of individual electron spins in both dopants and gated quantum dots in Si. Each of these results has come with physics that was not anticipated from previous work in other material systems. These advances underline the significant progress toward the realization of spin quantum bits in a material with a long spin coherence time, crucial for quantum computation and spintronics.