Issue 6

Sensors & Actuators Conference Series

Ashutosh Tiwari

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 678-678
DOI: 10.5185/amlett.2017/6001

International Association of Advanced Materials is pleased to announce Sensors & Actuators Conference Series in Asia, Europe and America with collaboration of VBRI Press AB, Sweden. The conference series are dedicated on the technology and systems in the field of sensors, actuators, microsystems and their developments, and major challenges in research & developments and markets.

Bilayered vanadium oxide as the host material for reversible beyond lithium ion intercalation

Mallory Clites; Bryan W. Byles; Ekaterina Pomerantseva

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 679-688
DOI: 10.5185/amlett.2017.1536

Bilayered vanadium oxide has emerged as a high-performance cathode material for beyond lithium ion (BLI) battery systems including Na-ion batteries, Mg-ion batteries, and pseudocapacitors. The major structural feature of bilayered V2O5 that makes it attractive for such applications is its large interlayer spacing of ~10-13 Å. This spacing can be controlled via the interlayer content, which can consist of varying amounts of structural water and/or inorganic ions, resulting in numerous chemical compositions.  Further, bilayered V2O5 can be synthesized via a number of different methods, resulting in morphologies that include xerogel, aerogel, thin films, and 1-D nanostructures. The interlayer spacing, content, and material morphology can all affect the electrochemical performance of this materials family, and in this review, we discuss the role of each of these factors in the reversible cycling of charge-carrying ions beyond lithium.  The different bilayered V2O5 synthesis methods and resulting compositions are reviewed, and important structure-property-performance insights into the reversible insertion/ extraction of larger/multivalent ions into the bilayered V2O5 structure are highlighted. 

Bi-criteria optimization in designing magnetic composites

Krzysztof Z. Sokalski; Barbara Slusarek; Marek Przybylski

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 689-694
DOI: 10.5185/amlett.2017.1441

A novel algorithm for designing the values of the technological parameters for the production of soft magnetic composites (SMCs) was created. These parameters are the hardening temperature T and the compaction pressure p < /em>. These parameters enable us to optimize the power losses and magnetic induction. The advantage of the presented algorithm lies in bi-criteria optimization. The crucial role played by the presented algorithm is scaling, pseudo equation of state and fixed point. On this basis, mathematical models of power losses and magnetic induction were created. The model parameters were calculated on the basis of the power loss characteristics and hysteresis loops. The created optimization system was applied to specimens of Somaloy500. The obtained output consists of a finite set of feasible solutions. To select a unique solution, an additional criterion was formulated. 

Development of new Al-Cu-Si alloys for high temperature performance

Samuel A. Awe; Salem Seifeddine; Anders E. W. Jarfors; Young. C. Lee; Arne K. Dahle

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 695-701
DOI: 10.5185/amlett.2017.1471

In a quest for developing new lightweight metal alloys that can perform excellently at elevated-temperatures (from 300°C to 400 °C), a ternary eutectic Al-Cu-Si alloy was exploited to gain a deeper understanding of the alloy system and its suitability for high temperature applications. The studied alloys, with chemical composition of Al-27%Cu-5%Si (by weight percent) with Ni addition in the range of 0 to 1.5%wt, were cast in a rapid solidification casting technique. The solidification characteristics of the alloy was studied using the Thermo-Calc software. Microstructures were characterized in a scanning electron microscope coupled with energy dispersive spectrometry (SEM-EDS). Finally, the elevated-temperature tensile properties of the alloys were investigated. Comparing the microstructures and mechanical properties of the Al-Cu-Si(-Ni) alloys with conventional A319 Al- alloy, the refined microstructure with dispersed Ni intermetallic particles formed in the as-cast Al-Cu-Si(-Ni) alloys delivers improved elevated temperature properties. In particular, the yield strength and ultimate tensile strength of the new alloy with 1.5% Ni at 400˚C were observed to be 220% and 309% higher, respectively, than for conventional A319 reference alloy.

Enhancement of ferromagnetism by substituting Cu for Mn in Ni-Mn-In-B Heusler alloys

Sudip Pandey; Abdiel Quetz; Anil Aryal; Ahmad Us Saleheen; Igor Dubenko; Dipanjan Mazumdar; Shane Stadler; Naushad Ali

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 702-706
DOI: 10.5185/amlett.2017.1403

The effects of substituting Cu for Mn on the magnetocaloric, transport, and thermomagnetic properties of Ni50Mn35-xCuxIn14B (x = 0, 1.25, 2.0) Heusler alloys were studied. It has been found that the magnitude of the magnetization jump at the martensitic transformation decreased with increasing Cu concentration. Smaller magnetic entropy changes (∆SM) were observed for the alloys with higher Cu concentrations. A decrease in the resistivity was observed with increasing Cu concentration. The magnetoresistance was dramatically suppressed with increasing Cu concentration due to the weakening of the antiferromagnetic (AFM) interactions in the martensitic phase. The experimental results demonstrate that Cu in Ni50Mn35-xCuxIn14B Heusler alloys suppresses the AFM interactions and enhances the ferromagnetic (FM) interactions in these alloys. Possible mechanisms responsible for the observed behavior are discussed.

Stability behavior of chemically synthesized organic electrolyte salts and methylammonium lead halide perovskite light harvester

Rajan Kumar Singh; Neha Jain; Jai Singh; Ranveer Kumar

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 707-711
DOI: 10.5185/amlett.2016.6953

This is the first time that a highly purified white organic electrolyte salts (OES), Methylammonium iodide, CH3NH3I (MAI) and Methylammonium chloride, CH3NH3Cl (MACl) have been successfully synthesized by a new technique, high vacuum oven evaporation method (HVOE), which is inexpensive and less time consumable. Thermal stability of organic salt, pure and mixed perovskite light harvester materials (PLHM) are studied by STA (DTG/DTA). CH3NH3I and CH3NH3Cl undergo ~100% weight loss in one step, at temperature 310 o C and 350 o C, respectively. Additionally, CH3NH3PbI3 is more thermally stable than mixed halide perovskite CH3NH3PbI3-xCl. Stability behavior of organic salts and CH3NH3PbI3-xClx is analyzed by Raman study which indicates that organic salts are stable in ambient conditions and CH3NH3PbI3-xClx   is not stable in ambient condition. Different stretching and banding modes of organic and inorganic materials are indentified by study of Raman spectra. 

Rheology of high melt strength polypropylene for additive manufacturing

Ralf Jagenteufel; Thomas Hofstaetter; Florian Kamleitner; David B. Pedersen; Guido Tosello; Hans N. Hansen

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 712-716
DOI: 10.5185/amlett.2017.1450

Rheological measurements of high melt strength polypropylene (HMS-PP) were used in order to generate master curves describing the shear-dependent viscosity in comparison to acrylonitrile butadiene styrene copolymer (ABS). The latter material showed specific disadvantages in terms of thermal stability, whereas HMS-PP showed a more stable behavior at the investigated temperatures. Hereafter, the material was used in a fused deposition modeling additive manufacturing process, focusing on the investigation of possible improvements of HMS-PP over ABS. Based on the extrusion parameters for ABS, adapted parameters for HMS-PP were determined using a fused deposition modeling test bench. The rheological survey clearly showed changes in the melt viscosity of both ABS and HMS-PP due to thermal degradation. However, the comparison of rheological data of the virgin materials with those of printed material showed negligible changes. This leads to the conclusion that the thermal degradation of HMS-PP and ABS during the fused deposition modeling process is negligible, due to the short exposure time to elevated temperatures.

Mechanical behavior and fracture surface characterization of liquid-phase sintered Cu-Sn powder alloys

Ahmed E. Nassef; A.I. Alateyah; Medhat A. El-Hadek; W. H. El-Garaihy

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 717-722
DOI: 10.5185/amlett.2017.1485

In this study, elemental Cu and Sn powder were mechanically mixed forming different Cu-Sn alloys. To ensure uniformity of the particle shapes, the Cu, and Sn were mechanically milled and mixed in an agate rock mortar, with high energy ball mill for half an hour, with different weight ratios according to the composition design. The milling of the powders resulted in uniform sphere-like particles for Cu–Sn alloys. Hot compaction was performed in a single acting piston cylinder arrangement at room temperature. All hot pressed MMCs were heat-treated at about 550°C to allow the atoms to diffuse randomly into a uniform solid solution, as liquid phase sintering. Vickers micro-hardness measurements were carried out for the hot-pressed Cu–Sn alloys. Cylindrical specimens of aspect ratio of ho/do = 1.5 were tested under frictionless conditions at the compression platen interface. Charpy transverse rupture strength had been used to determine the fracture strength of the different Cu-Sn alloys. Fracture surface features of the different Cu-Sn alloys were characterized using scanning electron microscopy. It had been found that, the 85%Cu–15% Sn alloy revealed an increase of hardness values, a decrease of the yield strength, and an increase in the impact energy by 26.2, 23, and 18.7%; respectively, compared with the Sn-free alloy. The Cu-Sn alloys showed an apparently classical inclined fracture surface, at about 45 o with the applied stress axis, which was similar to what’s obtained for a diversity of hard metals. 

New effective luminescent materials based on the Sm-doped borate glasses

Bohdan V. Padlyak; Ihor I. Kindrat; Radoslaw Lisiecki; Volodymyr T. Adamiv; Ihor M. Teslyuk

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 723-734
DOI: 10.5185/amlett.2017.1436

The spectroscopic and radiative properties of the Sm-doped borate glasses with Li2B4O7, LiKB4O7, CaB4O7, and LiCaBO3 basic compositions as new luminescent materials have been investigated and analysed. The borate glasses of high chemical purity and optical quality, doped with Sm2O3 in amounts of 0.5 and 1.0 mol. % were obtained from corresponding polycrystalline compounds in the air atmosphere using standard glass synthesis technology. The spectroscopic properties of obtained Sm-doped glasses were studied using electron paramagnetic resonance (EPR), optical absorption, photoluminescence, and decay kinetics techniques. The Judd–Ofelt theory had been used for analysis of the optical absorption spectra and calculation of the phenomenological intensity parameters (Ω2, Ω4, Ω6). Radiative properties such as transition probabilities (Arad), branching ratios (βexp < /sub> and βrad), stimulated emission cross-sections (σe), and radiative lifetimes (τrad) were estimated for 4 G5/2 → 6 HJ (J = 5/2, 7/2, 9/2, and 11/2) emission transitions of the Sm 3+ ions in the Li2B4O7:Sm, CaB4O7:Sm, and LiCaBO3:Sm glasses containing 1.0 mol. % Sm2O3. The luminescence kinetics of Sm 3+ centres in the investigated glasses are characterised by a single exponent decay with typical lifetimes, which depend on the basic glass composition and Sm impurity concentration. Experimental lifetimes (τexp < /sub>) have been compared with those calculated (τrad) and quantum efficiencies (η) of the Sm 3+ emission transitions were estimated. The calculated high quantum efficiencies (~ 80 %) and measured high quantum yields of luminescence (~ 14 – 21 %) clearly show that the investigated glasses belong to very promising materials for luminescent and laser applications.

Combustion synthesis and characterization of Sm3+ and Tm3+ co-activated yttrium orthovanadate phosphate

Selepe Joel Motloung; Kamohelo George Tshabalala; Odireleng Martin Ntwaeaborwa

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 735-740
DOI: 10.5185/amlett.2017.1405

Samarium (Sm 3+ ) and thulium (Tm 3+ ) co-activated yttrium orthovanadatephosphate YV0.5P < sub>0.5O4: Sm 3+ , Tm 3+ powder phosphors were synthesized by solution combustion method and were annealed at 900 o C for 2 hours. The x-ray diffraction patterns confirmed that the tetragonal structure of YV0.5P < sub>0.5O4 was crystallized. The patterns consisted of peaks from YVO4 and YPO4 suggesting that our product was an admixture of both compounds. The scanning and transmission electron microscopy image showed an agglomeration of particles with different sizes and shapes. The UV-vis reflectance spectra showed a broad absorption band extending from 200 — 550 nm associated with the O→V charge transfer transitions of [VO4] 3− .  The photoluminescence (PL) data of singly doped phosphors showed one blue emission peak at 477 nm ( 1 G4—  3 H6) and three emission peaks at 567 nm ( 6 G5/2 —  6 H5/2), 603 nm ( 6 G5/2 —  6 H7/2) and 650 nm ( 6 G5/2 —  6 H9/2) corresponding to transitions of Tm 3+  and Sm 3+  ions respectively. The PL data from the Sm 3+ - Tm 3+ co-doped systems demonstrated an enhancement of visible emission of Tm 3+ by down-conversion process that involves energy capture by the host last and Sm 3+ that was subsequently transferred to Tm 3+ .  These materials are evaluated as possible candidates to improve the power conversion efficiency of dye-sensitized solar cells.

Impregnation of kraft paper support with polylactic acid multilayers

Sandra Rivero; Javier Lecot; Adriana Pinotti

Advanced Materials Letters, 2017, Volume 8, Issue 6, Pages 741-751
DOI: 10.5185/amlett.2017.7107

PLA coating on Kraft paper is very promising systems for food packaging, and has potential environmental advantages over conventional synthetic paper coatings. This work was focused on: (i) analyzing the physicochemical, thermal and microstructural properties of PLA films; (ii) developing and studying multilayer systems obtained by impregnation of Kraft paper with different layers of PLA solution; (iii) evaluating the influence of PLA layers on the support cellulosic properties. The PLA coating improves packaging material performance and hence the functional properties of Kraft paper. The impregnation of hygroscopic materials as the Kraft paper with PLA was an alternative interesting to obtain more hydrophobic matrices. The assembled materials attained were heat-sealed. Furthermore, the use of PLA adds to potential food applications, a renewable resource value obtained from sources agricultural. The design of this multilayer support also allows its extension to other media such as paperboard. Moreover, the addition of 4 or 5 layers favourably modified the assembled system properties. Increasing even further the number of PLA layers, system properties hardly underwent a significant improvement. Consequently, the selection of the number of PLA layers would be a response to a relationship of commitment between the increase in the cost and the enhancement of the properties.