Sodium Hypophosphite Research Articles

Effect of Etching and Electroless Plating Time on Contact Angle of Acrylonitrile Butadiene Styrene for 3D-Printed Substrates

Acrylonitrile Butane Styrene (ABS) is a type of polymer that can be metallized with metal through the electroless plating process so as to produce a strong and economical layer bond compared to metal. In this study, ABS plastic will be coated with nickel and the contact angle of ABS after the coating process will be examined. The first step is the etching process for 55 and 75 minutes using chromic acid to improve the adhesiveness and uniformity of the coating metal later. After the etching process is complete, then the surface roughness test is carried out using Mitutoyo SJ 201 Surface Roughness. Furthermore, the activation process with stannous chloride as a catalyst is carried out to accelerate the deposition of metal particles on the substrate surface so that during the electroless plating process the polymer turns into a conductor. Then the electroless plating process with time variations of 15, 25, 35, 45, 55 minutes using nickel sulfate, ammonium chloride, sodium hypophosphite, and sodium hydroxide to deposit nickel metal on the ABS surface. The results of the coating are then analyzed for surface topography using AFM and SEM, as well as investigating the contact angle of the droplets that are dropped on the coated ABS surface. It can be said that the etching variation of 55 minutes electroless nickel plating 75 minutes is the most hydrophobic because it has the largest contact angle and the smoothest surface topography compared to other variations.

P-doped BiOCl for visible light photodegradation of tetracycline: An insight from experiment and calculation

A novel n-type phosphorus-doped bismuth oxychloride (P-BiOCl) photocatalyst was synthesized through facile one-step hydrothermal approach with sodium hypophosphite (NaH2PO2) addition, which is of extraordinarily high efficiency for tetracycline (TC) degradation under visible light. The physicochemical properties of the P-BiOCl sample were characterized by XRD, Raman, FTIR, XPS, AFM and (HR)TEM. The inorganic phosphorus sources and P/Bi ratios were optimized, and P-BiOCl remained high TC photodegradation efficiency after six cycles under visible light. The experimental and calculational results were combined to investigate the underline mechanisms: P atoms entered into the lattice of BiOCl by partially replacing Cl atoms, and then formed a midgap impurity level. The introduction of P heteroatom broadens bandgap, generates a new electron channel to facilitate electron transfer and inhibit carrier recombination. Moreover, P-doping enlarges specific surface area, increases oxygen adsorption and alters the conduction band position more negative, thus producing more active O2·- for TC degradation. Additionally, the photodegradation pathway of TC is proposed based on the results of Fukui index and LC-MS/MS.

Parametric optimization of electroless Ni-P-CNT coating using genetic algorithm to maximize the rate of deposition

To improve the surface property of 99% pure copper substrate Electroless Ni-P-CNT coating was deposited. The effect of the elements of the coating bath on the rate of mass deposition has been examined and discussed in this study. The first order regression equation has been developed to predict the rate of deposited mass per unit area. The Student’s t test have exhibited that the concentrations of Nickel Sulphate, Sodium hypophosphite and the carbon nanotubes (CNT) significantly affect the rate of deposition of the electroless Ni-P-CNT coating. A response order response surface model has been developed to consider the effect of curvature in predicting the response. The response surface and counter plots reveal that the variations in concentration of the individual process parameters influence the deposition rate dramatically. The F-test has confirmed that the predicted response surface equation shows an excellent fitting with the observed data. The optimum concentrations of Nickel Sulphate, Sodium hypophosphite and carbon nanotubes in the coating bath have been evaluated using genetic algorithm to maximise the rate of deposition of electroless Ni-P-CNT composite coating. The results of the genetic algorithm are consistent with the results of the confirmation run.

Selective reduction of aromatic halonitroarene to corresponding amine with Ru-gC3N4 as a catalyst in presence of sodium hypophosphite as a hydrogen source

This study reports an efficient heterogeneous catalyst Ru-gC3N4 (Ru-GCN) developed for the selective hydrogen transfer reduction reaction of nitroarenes to the corresponding amine. It helps to avoid multistep reaction in the field of organic synthesis. The catalyst Ru-gC3N4 shows excellent activity under the mild reaction parameters via using sodium hypophosphite as a hydrogen source and can be effective after many cycles without significant change in activity. The simply separable and recyclable heterogeneous Ru-gC3N4 catalyst is straight forward to operate, non-toxic, eco-friendly and at the same time replaces the comprehensive use of high pressurized hydrogen cylinder. Various types of material characterization and spectral methods such as PXRD, FTIR, SEM, TEM, XPS, and TGA are used to characterize the Ru-gC3N4 catalyst. All these properties such as good reusability and retained activity make our process sustainable and environmentally friendly. Aiming towards industrial potentiality, a gram scale experiment was reported using the developed protocol.

Effects of Triple Modification Of Sodium Hypophosphite on Structure and Electrochemical Performances of Lithium-Rich Manganese-Based Cathode Materials

Effects of Triple Modification Of Sodium Hypophosphite on Structure and Electrochemical Performances of Lithium-Rich Manganese-Based Cathode Materials

BTCA ve CA Çapraz Bağlayıcılar Kullanılarak Pamuklu Kumaşın Kopma ve Yırtılma Mukavemetinin Geliştirilmesi

Polycarboxylic acids are used as crosslinking agents with sodium hypophosphite which do not contain formaldehyde. In this study, breaking strength, breaking elongation and tear strength of cotton(twill weave)fabric samples were determined by using twill fabrics, six different coating recipes, produced with 100% cotton yarns. The results of breaking strength, breaking elongation and tear strength testing were compared according to the fabric structure, coating recipes and crosslinker structure statistically. A significant increase in tensile strength was observed after coating with 1g Cu2O|

Effect of chemical modification and heat treatment on biological durability and dimensional stability of Pinus roxburghii Sarg.

Background: Depleting supplies of wood species with inherent natural durability has resulted in the focus being shifted to non-durable plantation grown and imported timber. Despite its abundant availability and better treatability, the use of Pinus roxburghii is limited to packing cases, crates, shutters, door and window frame, carpentry and joinery items due to its nondurable nature. Hence, to promote use of such timber for applications such as decking, cladding and facade elements chemical modification with a combination of citric acid and sodium hypophosphite, and heat treatment were explored to improve its service life. Methods: Chemical modification was performed using a water solution of citric acid (6.9%) and sodium hypophosphite (6.5%) followed by curing at 140°C for 8 hrs. Dimensional stability was determined by estimating the volumetric swelling coefficient and anti-swelling efficiency (ASE) of treated and control samples. Durability against fungus and termites was evaluated using a soil block bioassay and termite mound test as per standard methods. Results: Both chemical modification and heat treatment of P. roxburghii resulted in enhanced dimensional stability and biological durability compared to the untreated controls. Chemical modification and heat treatment resulted in 23.05% and 18.37% volumetric ASE, respectively. Results showed that a highly perishable species became significantly more durable after chemical modification, exhibiting 5–6 times less mass loss by termites in comparison to the controls. Wood samples modified with citric acid showed excellent resistance to both white and brown rot fungi and exhibited 14-15 times less reduction in mass compared with untreated samples. Conclusions: Citric acid chemical modification is an environment friendly process that improved the dimensional stability as well as resistance against biodegradation. These studies may provide valuable inputs to establish this mode of chemical modification as a cost-effective alternative to other chemicals for wood preservation. The concentrations of the chemicals and temperature for fixation may be varied to establish an optimum combination for best output.

Characterization and photocatalytic activity of titanium dioxide powder treated with PH3 gas

NH3 treatment for nitrogen doping to metal oxides is widely used as a method of band gap narrowing. However, PH3 treatment of titanium dioxide(TiO2) powders has not yet been established. In the present study, PH3 treatment of TiO2 was attempted by heating TiO2 powders and solid-state sodium hypophosphite in a sealed ampoule. The color of the powders changed from colorless for untreated TiO2 to beige for TiO2 treated at 250, 290, 350 °C, or to gray for TiO2 treated at 450 °C. X-ray photoelectron spectroscopy (XPS) analysis of the treated TiO2 revealed that the phosphorus was in a phosphate form and that a part of Ti4+ in TiO2 was reduced to Ti3+. The absorption spectra and the XPS data suggested the generation of oxygen vacancies. Adsorption experiments of methylene blue and Eosin Y onto the treated TiO2 indicated the presence of phosphate on the surface of TiO2. X-ray diffraction (XRD) analysis indicated that the crystallite sizes of the treated TiO2 increased with increasing in temperature. Photodegradation rates of the pigments by the treated TiO2 under UV light depended on phosphate, oxygen vacancy and crystallinity. PH3 treatment of crystalline TiO2 were found to give priority to phosphate formation in contrast to NH3 treatment for nitrogen doping.

Ester crosslinking on cellulose with pyromellitic acid for anti-wrinkle finishing

Aromatic carboxylic acids were investigated for anti-wrinkle finishing on cotton fabrics as it caused less damage to fibers. However, its application was limited to its poor water solubility. In this study, pyromellitic acid (PMA) was applied for anti-wrinkle finishing on fabric in 30%(w/w) ethanol solution instead of water. The optimum process parameters, such as concentration, bath pH, catalyst dosage, curing condition, were analyzed by orthogonal test for crosslinking cellulose. The surface morphology changes of treated fibers were recorded by scanning electron microscope (SEM). The possible reactive mechanism between PMA and cellulose was discussed by means of Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyses (TGA), in-situ temperature-dependent Fourier transform infrared spectroscopy (FTIR). The results demonstrated that the optimized process for PMA crosslinking cellulose was PMA 0.3 mol/L, bath pH 1.5, sodium hypophosphite (SHP, NaH2PO2) 0.10 mol/L, baking condition 180 °C*1.5 min. The bath pH and curing temperature were the primary factors for fabric wrinkle resistance and strength lose, respectively. After repeated laundering, the strength loss of treated samples with PMA was obviously lower than that of aliphatic carboxylic acid and dimethylol dihydroxy ethylene urea (DMDHEU, 2 D resin). Meanwhile, PMA had less effect on fiber surface morphology and the fiber strength lose was mainly from the damage accumulation of macromolecular chains in fibers. The SHP catalytic action in PMA was much lower than that in aliphatic carboxylic acids for esterification. Moreover, the ortho carboxylic groups on PMA not only esterified with cellulose directly, but also dehydrated into anhydride and further reacted with cellulose. The crosslinking between PMA and cellulose was mainly by direct esterification rather than indirect esterification by anhydride intermediate. The results provided new insights for the application of insoluble crosslinker on cellulose.

CoP/Co2P hollow spheres embedded in porous N-doped carbon as highly efficient multifunctional electrocatalyst for Zn–air battery driving water splitting device

Highly efficient multifunctional earth-abundant elements based electrocatalysts are key important for development of clean energy transformation technologies, such as metal-air batteries, fuel cells and water electrolysis. Herein, composite catalysts of N-doped carbon wrapping CoxP hollow spheres have been successfully prepared by pyrolysis of precursors from self-assembly of cobalt salt, terephthalic acid and PVP followed by carbonization and phosphatization in the presence of sodium hypophosphite. The resulted composites showed high specific surface areas, pore volumes and nitrogen contents, especially more than 47% of pyridinic-N. The electrocatalytic activity tests showed that the optimized CoxP-NC-420 sample exhibited superior multifunctional performances and high stabilities for hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) under alkaline conditions. A low overpotential of 125/273 mV (at 10 mA cm−2) and Tafel slope of 66/81 mV dec−1 was obtained for HER and OER, respectively. As for ORR, as high as 0.860 V of half-wave potential was obtained, which is even 36 mV higher than that of Pt/C (20%). The catalyst also exhibited high practical performances on water electrolysis and Zn−air battery. Only 1.61 V of cell voltage was needed to reach 10 mA cm−2 for water electrolysis, and 1.374 V of open-circuit potential and 52 mW cm−2 of power density were obtained for Zn−air battery, which was 16 mW cm−2 higher than that of Pt/C (20%). Moreover, a highly effcient self-driven water electrolyzer has been designed with CoxP-NC-420 as both anode and cathode catalyst, powered by two-series-connected CoxP-NC-420-based Zn–air batteries. This work provides a new strategy for fabrication of non-precious multifunctional electrocatalysts.

Suppressing photoinduced charge recombination at the BiVO4||NiOOH junction by sandwiching an oxygen vacancy layer for efficient photoelectrochemical water oxidation

Nickel oxyhydroxide (NiOOH) is regarded as one of the promising cocatalysts to enhance the catalytic performance of photoanodes but suffers from serious interfacial charge-carrier recombination at the photoanode||NiOOH interface. In this work, surface-engineered BiVO4 photoanodes are fabricated by sandwiching an oxygen vacancy (Ovac) interlayer between BiVO4 and NiOOH. The surface Ovac interlayer is introduced on BiVO4 by a chemical reduction treatment using a mild reducing agent, sodium hypophosphite. The induced Ovac can alleviate the interfacial charge-carrier recombination at the BiVO4||NiOOH junction, resulting in efficient charge separation and transfer efficiencies, while an outer NiOOH layer is coated to prevent the Ovac layer from degradation. As a result, the as-prepared NiOOH-P-BiVO4 photoanode exhibits a high photocurrent density of 3.2 mA cm−2 at 1.23 V vs. RHE under the irradiation of 100 mW/cm2 AM 1.5G simulated sunlight, in comparison to those of bare BiVO4, P-BiVO4, and NiOOH-BiVO4 photoanodes (1.1, 2.1 and 2.3 mA cm−2, respectively). In addition to the superior photoactivity, the 5-h amperometric measurements illustrate improved stability of the surface-engineered NiOOH-P-BiVO4 photoanode. Our work showcases the feasibility of combining cocatalysts with Ovac, for improved photoactivity and stability of photoelectrodes.

Ru-gC3N4 Catalyzed Hydrodebenzylation of Benzyl Protected Alcohol and Acid Groups Using Sodium Hypophosphite as a Hydrogen Source

A straightforward process for hydrodebenzylation of benzyl protected acid and alcohol derivatives to the corresponding acids and alcohols using sodium hypophosphite in the presence of Ru-GCN catalyst is reported. The developed Ru-GCN catalyst is cost effective compared to other noble metal-based catalysts and has been explored to exhibit excellent activity for catalytic hydrodebenzylation reactions under moderate reaction conditions. The non-corrosive sodium hypophosphite has been found as a better hydrogen donor compared to alkali metal formats in presence of Ru-GCN catalyst. The stated catalyst was characterized using several spectrometric and material characterization methods such as PXRD, IR, SEM, TEM, XPS, and TGA. The Ru-GCN catalyst corroborated good reusability and stability for multiple cycles. The catalyst preparation is facile and the developed process is simple and safe as it avoids use of high hydrogen pressure. The developed protocol can also be replicated on industrial scale on account of excellent recyclability and retained activity after multiple cycles and makes the process sustainable. Gram scale reaction was performed to verify the industrial potential of reported catalyst.

Synthesis of n‐alkylated quaternary ammonium chitosan and its long‐term antibacterial finish for rabbit hair fabric

AbstractIn this work, n‐alkyl chitosan (N‐CTS) was obtained by alkylation modification of chitosan with n‐butylaldehyde using Schiff alkali method. The etherifying agent 3‐chloro‐2‐hydroxypropyl triethylammonium chloride (CHPTAC‐ethyl) was synthesized from triethylamine and epichlorohydrin. The N‐CTS and CHPTAC‐ethyl were etherized to finally synthesize n‐alkyl quaternary ammonium chitosan (N‐CCTS). Scanning electron microscope, X‐ray diffractometer, Fourier transform infrared, X‐ray photoelectron spectroscopy, and 13CNMR were used to characterize the surface morphology and chemical structure. Viscosity method and spectrophotometry were used to determine its physical and chemical properties. The etherification reaction mechanism was studied systematically and the influence of reaction conditions on the degree of substitution and solubility of N‐CCTS was investigated. The minimum inhibitory concentration (MIC) of N‐CCTS against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was both 0.15 g/L, which was superior to the MIC value of natural chitosan. N‐CCTS was used to finish rabbit hair fabric with citric acid as cross‐linking agent and sodium hypophosphite as catalyst. The antibacterial and washing resistance of the product were investigated. After 25 times of washing, the antibacterial rate of N‐CCTS against E. coli and S. aureus remained stable at about 90%, and the antibacterial rate was higher than that of N‐CTS and natural chitosan, and it was a kind of natural polymer long‐acting antibacterial finishing agent for rabbit hair fabric.

Charactarization of Formaldehyde-Free Electro-Less Copper Plating for Semi-Additive Process

Abstract Typically, industrial electroless copper plating solutions use formaldehyde as a reducing agent. However, since formaldehyde has a strong odor and is a carcinogenic substance, it has an adverse effect on the working environment and the human body. Therefore, an electro-less copper plating solution containing no formaldehyde is desired. We have researched and developed a formaldehyde-free electro-less copper plating solution and evaluated its properties for applications such as panel level package (PLP). Price is the main reason for selecting agents with reducing power to copper for use in the plating market. We promoted to develop the plating solution using sodium hypophosphite as a reducing agent, which is the next least expensive after formalin solution. The reducing agent used in this plating solution has low catalytic activity for copper. As a result, when the palladium catalyst on the resin is covered with copper plating, the plating deposition rate is reduced. In order to prevent the deposition reaction from stopping during plating, a metal salt with high catalytic activity for this reducing agent is plated. The method of adding to the liquid was carried out. As a result, the bath stability of the development bath is excellent because no Cannizzaro reaction or disproportionate reaction of the first copper ion occurs, unlike ordinary electro-less copper plating solutions. This is a major advantage in terms of running costs and requirements for ancillary the plating equipment. When the characteristics of the plating film by development bath were examined, the internal stress was found to be as low as 150 MPa on the tensile side. The adhesion to the ABF resin was high, ranging from 500 to 700 gf/cm. Also it exhibits excellent plating deposition inside blind via hole (BVH) which is equivalent to that of general electro-less copper plating solution, it can be applied to semi-additive process package boards where electro-less copper plating film is etched.

Synthesis of copper nanoparticles with controllable crystallinity and their photothermal property

Synthesis of copper (Cu) nanoparticles in aqueous solution is of great challenge due to their tendency to oxidization upon exposure to air. In this work, well crystallized Cu nanoparticles with diameters of about 80 nm were successfully prepared in aqueous solution via simply reducing copper salts by sodium hypophosphite at presence of hydrochloric acid, and with polyacrylamide (PAM) as the capping agent. Experimental results showed that the presence of H+ facilitated formation of Cu nanoparticles and the crystallinity of the nanoparticles is highly dependent on Cl- concentration. Meanwhile, the size and morphology of the resulted nanoparticles could be controlled by concentration of PAM. The obtained Cu nanoparticles were further uniformly distributed in polyvinyl alcohol, forming a Cu-PVA hydrogel, which showed a significant photothermal conversion efficiency as high as 23.9% upon laser illumination. Continuous cycling test confirmed the long-term photothermal performance of the Cu-PVA hydrogel, and a bacterial killing efficiency of more than 99% could be realized after incubating it with E. coli under laser irradiation for 10 min. Besides, the prepared Cu nanoparticles may find practical applications in electronic and catalytic areas where the properties are closely related to nanoparticles crystallinity.

Characterisation of Moisture in Scots Pine (Pinus sylvestris L.) Sapwood Modified with Maleic Anhydride and Sodium Hypophosphite

In this study, the wood–water interactions in Scots pine sapwood modified with maleic anhydride (MA) and sodium hypophosphite (SHP) was studied in the water-saturated state. The water in wood was studied with low field nuclear magnetic resonance (LFNMR) and the hydrophilicity of cell walls was studied by infrared spectroscopy after deuteration using liquid D2O. The results of LFNMR showed that the spin–spin relaxation (T2) time of cell wall water decreased by modification, while T2 of capillary water increased. Furthermore, the moisture content and the amount of water in cell walls of modified wood were lower than for unmodified samples at the water-saturated state. Although the amount of accessible hydroxyl groups in modified wood did not show any significant difference compared with unmodified wood, the increase in T2 of capillary water indicates a decreased affinity of the wood cell wall to water. However, for the cell wall water, the physical confinement within the cell walls seemed to overrule the weaker wood–water interactions.

Dyeing Property Improvement of Madder with Polycarboxylic Acid for Cotton.

Cotton fabrics were dyed with the madder and compounds of citric acid (CA) and dicarboxylic acids [tartaric acid (TTA), malic acid (MLA), succinic acid (SUA)] as cross-linking agents and sodium hypophosphite (SHP) as the catalyst. The molecular structures and crystal structures of the dyed cotton fabrics were analyzed using Fourier-transform infrared spectroscopy (FTIR) and X-ray diffractometry (XRD), respectively. The results showed that the polycarboxylic acids esterified with the hydroxyl groups in the dye and cellulose, respectively, and the reaction mainly occurred in the amorphous region of the cotton fabric. Compared with the direct dyed cotton fabric, the surface color depth (K/S) values of the CA, CA+TTA, CA+MLA, CA+SUA cross-linked dyed cotton fabrics increased by approximately 160%, 190%, 240%, 270%, respectively. The CA+SUA cross-linked dyed cotton fabric achieved the biggest K/S value due to the elimination of the negative effect by α-hydroxyl in TTA and MLA on esterification reaction, and the cross-linked dyed cotton fabrics had great levelness property. The washing and rubbing fastness of the cross-linked cotton fabrics were above four levels. The light resistance stability and the antibacterial property of the cross-linked dyed cotton fabrics was obviously improved. The sum of warp and weft wrinkle recovery angle (WRA) of the CA+SUA cross-linked dyed cotton fabric was 55° higher than that of raw cotton fabric, and its average UV transmittance for UVA was less than 5% and its UPF value was 50+, showing a great anti-wrinkle and anti-ultraviolet properties.

Performance evaluation of modified fabricated cotton membrane for oil/water separation and heavy metal ions removal

AbstractPreparation of effective membrane with special surface treatment for oil/water separation having promising future and low manufacturing cost. The suggested membrane was fabricated by a simple treatment via increasing the hydrophilicity of the cotton fabric surface. The cotton fabric was impregnated in poly(acrylic acid‐co‐N‐methylol acrylamide), poly(AA‐co‐NMA), where NMA acts as bonding agent. Sodium hypophosphite (SHP) was added to the modification solution to enhance the bonding between the cotton fabric and the PAA. The modified fabric was thermally dried and cured at different temperatures. It was found that, the presence of 3.5% NMA and addition of 5% SHP to the modification solution then curing at 190°C gave the highest amount of bonded PAA to the cotton fabric. The success of the modification process was confirmed by scanning electron microscope, Fourier transformer infrared and the increase in the contact angle of the cotton fabric after modification. Furthermore, the prepared membrane was evaluated for oil (n‐hexane, toluene, and petroleum ether)/water separation and also for heavy metal ions removal (Cd2+ and Co2+). Neutralization of the produced membrane with ammonium hydroxide resulting in a higher contact angle and consequently higher separation efficiency for oil/water mixtures and higher performance for heavy metal ions removal compared to the unneutralized one.

Advantage of Using NaH2PO2 over Alkali Metal Formates as a Hydrogen Source for Pd‐gC3N4 Catalyzed Hydro‐Dehalogenation of Aryl Halides

AbstractHalogenated and polyhalogenated aromatic compounds are known for their toxicity and effect on human health and the environment. These aromatic hydrocarbons have been widely used in pesticides, flame retardants, pharmaceuticals, and other industrial chemicals. The substitution of halogen atoms of aromatic halides by hydrogen atoms in the presence of a metal catalyst is an important organic transformation and is known as a catalytic hydro‐dehalogenation reaction. It is an important technique used for the treatment of halogenated industrial waste. Herein, we investigated the comparative hydro‐dehalogenation of aryl halides in the presence of Pd‐gC3N4 catalyst using various hydrogen transfer sources in an eco‐friendly manner. We also investigated the advantage of using sodium hypophosphite (NaH2PO2) as a hydrogen source for hydro‐dehalogenation in comparison to alkali metal formates. For hydro‐dehalogenation of 1 mmol of aryl halide, 2 equivalents of NaH2PO2 are used while 4 equivalents of KHCO2 are required in the presence of 3.8 wt % of Pd metal catalyst. The Pd‐GCN catalyst was characterized by various microscopic and spectral techniques such as PXRD, FTIR, SEM, TEM, XPS, and TGA, etc. A gram scale reaction was performed to analyze the industrial potential of the proposed catalytic system. Finally, the recyclability of Pd‐GCN was found excellent and the catalyst could run multiple cycles with sustained activity.

Magnetic Properties of Electrodeposited Cobalt-Platinum (CoPt) and Cobalt-Platinum-Phosphide (CoPtP) Thin Films.

CoPt and CoPtP thin films were synthesized using direct current (DC) aqueous electrodeposition from weak alkaline solutions. The basic plating solutions of binary CoPt thin films consisted of cobalt pyrophosphate [Co2P2O7] and chloroplatinic acid [H2PtCl6]. Various amounts of sodium hypophosphite [NaH2PO2] was added to deposit ternary CoPtP thin films. The film composition was adjusted by varying the several electrodeposition parameters including electrolyte composition, solution pH, and current density and correlated to their microstructure and magnetic property (i.e. coercivity and squareness). For the binary CoPt thin films, the maximum coercivities [in-plane coercivity (Hc,//) = ∼1,600 Oe, and perpendicular coercivity (Hc,⊥) = ∼2,500 Oe] were obtained from electrolytes containing 0.01 M H2PtCl6 + 0.04 M Co2P2O7 at current density (CD) of 7.5 mA cm−2. In the case of ternary CoPtP electrodeposits, the maximum coercivities (Hc,// = ∼2,600 Oe, and Hc,⊥ = ∼3,800 Oe) were achieved from baths containing 0.015 M H2PtCl6, 0.07 M Co2P2O7, 0.8 M NaH2PO2 at CD of 7.5 mA cm− 2 and solution pH 9. It was suggested that microstructure and magnetic properties are affected not only by the type of substrate but also by chemical compositions and electrodeposition conditions.