Synthesis and Quality of Cr-doped AlN Thin Films Grown by RF Sputtering

Pham Hong Quang,Tran Quang Hung,Ngo Xuan Dai,Tran Hoai Thanh,Kim CheolGi 한국자기학회 2007 Journal of Magnetics Vol.12 No.4

The AlCrN films were grown by RF reactive sputtering method under the selected conditions. The Cr concentration was varied by the number of Cr pieces placed on the Al target. The sample quality has been studied by XRD, Auger spectroscopy, optical absorption and electrical resistant measurements. The XRD and Auger results show that the samples consist of a major phase with the Al1-xCrxN formula, which has a hexagonal structure, and a few percents at. of oxygen, which may form Al₂O₃. There exist the Cr clusters in the samples with high concentration of Cr. The optical absorption measurement provides the information about the band gap that relates strongly to the quality of samples. The quality of samples is also clearly reflected in electrical measurement, i.e., the temperature dependence of resistance exhibits a semiconductor characteristic only for the samples that have no Cr cluster. In these cases, the values of ionization energies Ea can be derived from R(T) plots by using the function R(T) = Ro exp (Ea/kBT).

A self-encapsulated porous Sb-C nanocomposite anode with excellent Na-ion storage performance

Pham, Xuan-Manh,Ngo, Duc Tung,Le, Hang T. T.,Didwal, Pravin N.,Verma, Rakesh,Min, Chan-Woo,Park, Choong-Nyeon,Park, Chan-Jin The Royal Society of Chemistry 2018 Nanoscale Vol.10 No.41

<P>In this study, a self-encapsulated Sb-C nanocomposite as an anode material for sodium-ion batteries (SIBs) was successfully synthesised using an SbCl3-citrate complex precursor, followed by a drying and calcination process under an inert N2 atmosphere. When the molar ratio of SbCl3 to citric acid was varied from 1 : 1 to 1 : 4, the Sb-C nanocomposite with a molar ratio of 1 : 3 (Sb-C3) exhibited the highest specific surface area (265.97 m<SUP>2</SUP> g<SUP>−1</SUP>) and pore volume (0.158 cm<SUP>3</SUP> g<SUP>−1</SUP>). Furthermore, the Sb-C3 electrode showed a high reversible capacity of 559 mA h g<SUP>−1</SUP> at a rate of C/10 and maintained a high reversible capacity of 430 mA h g<SUP>−1</SUP> even after 195 cycles at a rate of 1C. The Sb-C3 electrode exhibited an excellent rate capability of 603, 445, and 357 mA h g<SUP>−1</SUP> at the rates of C/20, 5C, and 10C, respectively. Furthermore, a full cell composed of an Sb-C3 anode and a Na3V2(PO4)3 cathode exhibited good specific capacity and cyclability, making the Sb-C composite a promising anode material for high-performance SIBs.</P>

Photo induced NO₂ sensing properties of bismuth triiodide (BiI₃) nanoplates at room temperature

Hung, Pham Tien,Hien, Vu Xuan,Hoat, Phung Dinh,Lee, Sangwook,Lee, Joon-Hyung,Kim, Jeong-Joo,Heo, Young-Woo Elsevier 2019 Scripta materialia Vol.172 No.-

<P><B>Abstract</B></P> <P>Herein we report on the growth of layered BiI<SUB>3</SUB> nanoplates materials and their sensing properties of NO<SUB>2</SUB> under violet light illumination. The BiI<SUB>3</SUB> nanoplates were grown on a glass substrate using a chemical vapor deposition (CVD) system, with an average thickness of 30 nm and the lateral dimension of 150–170 nm. Their photo-induced sensing response for 20 ppm NO<SUB>2</SUB> and the response/recovery time are approximately ~11.2% and 18/36 s, respectively. The limit of detection (LOD) of NO<SUB>2</SUB> for the BiI<SUB>3</SUB> sensor is 25 ppb. A possible light-induced gas-sensing mechanism was proposed and investigated for the BiI<SUB>3</SUB> nanoplate.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

4-Mercaptobenzoic Acid Labeled Gold-Silver-Alloy-Embedded Silica Nanoparticles as an Internal Standard Containing Nanostructures for Sensitive Quantitative Thiram Detection

Pham, Xuan-Hung,Hahm, Eunil,Huynh, Kim-Hung,Son, Byung Sung,Kim, Hyung-Mo,Jeong, Dae Hong,Jun, Bong-Hyun MDPI AG 2019 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.20 No.19

<P>In this study, SiO2@Au@4-MBA@Ag (4-mercaptobenzoic acid labeled gold-silver-alloy-embedded silica nanoparticles) nanomaterials were investigated for the detection of thiram, a pesticide. First, the presence of Au@4-MBA@Ag alloys on the surface of SiO2 was confirmed by the broad bands of ultraviolet-visible spectra in the range of 320-800 nm. The effect of the 4-MBA (4-mercaptobenzoic acid) concentration on the Ag shell deposition and its intrinsic SERS (surface-enhanced Raman scattering) signal was also studied. Ag shells were well coated on SiO2@Au@4-MBA in the range of 1-1000 µM. The SERS intensity of thiram-incubated SiO2@Au@4-MBA@Ag achieved the highest value by incubation with 500 µL thiram for 30 min, and SERS was measured at 200 µg/mL SiO2@Au@4-MBA@Ag. Finally, the SERS intensity of thiram at 560 cm−1 increased proportionally with the increase in thiram concentration in the range of 240-2400 ppb, with a limit of detection (LOD) of 72 ppb.</P>

Proposal of Cross-platform Real-time Open Messaging System(ROMS) with Apache Cordova

Xuan-Qui Pham(팜소안쿠이),Pham Phuoc Hung(밤복홍),Ton Thi Kim Loan(톤띠김롼),Nguyen Dao Tan Tri(누엔다우탄틸리),Huu-Quoc Nguyen(누엔훠쿠크),Aymen Abdullah Alsaffar(아이만압둘라알사파르),Yunkon Kim(김윤곤),Eui-Nam Huh(허의남) 한국정보과학회 2015 한국정보과학회 학술발표논문집 Vol.2015 No.6

A Scheduling Mechanism for Cloud and Thick Client Collaboration

Pham Phuoc Hung(밤복흥),Xuan-Qui Pham(팜소안쿠이),Aymen Abdullah Alsaffar(아이만압둘라알사파르),Huu-Quoc Nguyen(응웬흐우꾸억),Ton Thi Kim Loan(톤띠김론),Sang-ho Na(나상호),Eui-Nam Huh(허의남) 한국정보과학회 2015 한국정보과학회 학술발표논문집 Vol.2015 No.6

Hydrazine detection by shape-controlled palladium nanostructures on carbon nanotube thin films

Xuan-Hung Pham,Minh-Phuong Ngoc Bui,Cheng Ai Li,한귀남,Muhammad Irfan,홍명효,성기훈 한국바이오칩학회 2013 BioChip Journal Vol.7 No.2

In this article, the electrodeposition of palladium (Pd) nanostructures on flexible and transparent single-walled carbon nanotube (SWCNT) thin films was described. Four different morphologies of Pd nanostructures were synthesized by controlling the potentials. Octahedral-like and flower-like nanostructures were observed at +0.3V and -0.1V, respectively. With a further driving potential decrease, cubic and spherical nanostructures were obtained in turn at 0.0V and -0.5V. The Pd nanostructures were confirmed by XRD data. Subsequently, the fabricated Pd nanostructures on SWCNT thin films were employed as electrodes for hydrazine detection. The electrochemical oxidation of hydrazine by Pd nanostructures was investigated by cyclic voltammetry and amperometry. As results, the specific sensitivities of four Pd nanostructures were 1123 μA mM cm-2 (octahedron), 899 μA mM cm-2 (flower), 827 μA mM cm-2 (cube), and 275μA mM cm-2 (sphere). The detection limits were 5.90μM (octahedron), 2.56 μM (flower), 2.85 μM (cube),and 4.83 μM (sphere).The morphology effect of Pd nanostructures on hydrazine oxidation is dependent on the relative fraction of (100), (110), and (111) facets which are associated with the shape. The (111) facet dominant Pd nanostructures exhibited the higher catalytic activities than Pd nanostructures with (100) and (110) facets.

Synthesis and quality of Cr-doped thin films grown by RF sputtering

Pham Hong Quang,Tran Quang Hung,Ngo Xuan Dai,Tran Thi Hoai Thanh,Kim CheolGi 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Sensitive and selective detection of 4-aminophenol in the presence of acetaminophen using gold–silver core–shell nanoparticles embedded in silica nanostructures

Xuan-Hung Pham,함은일,Kim-Hung Huynh,김형모,Byung Sung Son,Dae Hong Jeong,Bong-Hyun Jun 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.83 No.-

Toxic 4-aminophenol (4-AP) can be considered as a primary impurity during the synthesis and/or storageof N-acetyl-para-aminophenol (APAP). In this study, 4-AP was sensitively and selectively detected in thepresence of APAP using a gold–silver core–shell nanoparticle-embedded silica nanostructure(SiO2@Au@Ag). First, approximately 200 nm of SiO2@Au@Ag were successfully prepared based on theAu-seed (3 nm) mediated growth of Ag on the surface of SiO2 NP. Upon the incubation of 4-AP withSiO2@Au@Ag nanoparticles (NPs), the surface-enhanced Raman spectroscopy (SERS) intensity of 4-AP at1591 cm 1 increased proportionally in accordance with an increase in the concentration of 4-AP in therange of 0–800 mM, with a detection limit of 3.5 ppm. In addition, the APAP did not exhibit a significantRaman signal at high concentrations (5 mM) and under the NP incubation condition. In the presence of 1mM, 3 mM, and 5 mM of APAP, 4-AP was detected using SiO2@Au@Ag NPs within the range of 200–1000mM, although the slopes decreased from 0.083 cps/mM to 0.059 cps/mM, 0.068 cps/mM, and 0.035 cps/mM, respectively. This study provides a method for the detection of 4-AP in the presence of APAP by usingSiO2@Au@Ag for impurity detection in the pharmaceuticalfield.

Facile Method for Preparation of Silica Coated Monodisperse Superparamagnetic Microspheres

Pham, Xuan-Hung,Kyeong, San,Jang, Jaein,Kim, Hyung-Mo,Kim, Jaehi,Jung, Seunho,Lee, Yoon-Sik,Jun, Bong-Hyun,Chung, Woo-Jae Hindawi Limited 2016 Journal of nanomaterials Vol.2016 No.-

<P>This paper presents a facile method for preparation of silica coated monodisperse superparamagnetic microsphere. Herein, monodisperse porous polystyrene-divinylbenzene microbeads were prepared by seeded emulsion polymerization and subsequently sulfonated with acetic acid/H2SO4. The as-prepared sulfonated macroporous beads were magnetized in presence of Fe<SUP>2+</SUP>/Fe<SUP>3+</SUP>under alkaline condition and were subjected to silica coating by sol-gel process, providing water compatibility, easily modifiable surface form, and chemical stability. FE-SEM, TEM, FT-IR, and TGA were employed to characterize the silica coated monodisperse magnetic beads (~7.5 <I>μ</I>m). The proposed monodisperse magnetic beads can be used as mobile solid phase particles candidate for protein and DNA separation.</P>