Sodium hypophosphite

About: Sodium hypophosphite is a research topic. Over the lifetime, 1695 publications have been published within this topic receiving 15932 citations.

Microstructures and crystallization of electroless Ni-P deposits

Abstract: A study has been made of microstructures and crystallization of the electroless Ni-P deposits containing 11.3 to 23.0 at% P obtained from acidic nickel sulphate baths with sodium hypophosphite as a reducing agent by means of differential scanning calorimetry, X-ray diffractometry and hot stage transmission electron microscopy. The deposits containing low phosphorus content of 11.3 at% could be represented as an fcc Ni-P solid solution of 5 to 10 nm microcrystallites, whereas the deposits containing high phosphorus content were amorphous. The crystallization process of amorphous Ni-P solution involved more than one intermediate phases; precrystallized nickel or off-stoichiometric Ni3(P, Ni) or Ni5(P, Ni)2 phase in which some phosphorus sites are replaced by nickel atoms. The final equilibrium phases were bct Ni3P and fcc nickel crystals regardless of phosphorus content. The amorphous phase containing 20 to 22 at% phosphorus was the most stable among the amorphous Ni-P alloys.

Electroless plating of metallic features on nonmetallic or semiconductor layer without extraneous plating

Abstract: In the manufacture of a microelectronic component having metallic features on a polyimide layer, the metallic features being spaced from one another by gaps, at least some of which gaps have widths in a range from about one micron to about 500 microns, corrosion protection is provided by plating those features by electroless deposition of a nickel-phosphorus alloy forming a layer having a thickness in a range from about 200 Å to about 3000 Å, at a rate of about 100 Å per minute, in an aqueous plating bath comprising nickel sulfate hexahydrate in an amount of about 5.5 grams per liter, sodium hypophosphite in an amount of about six grams per liter, boric acid in an amount of about 30 grams per liter, sodium citrate in an amount of about 45 grams per liter, lead acetate in an amount of about one part per million by weight of lead, and a surfactant in an amount of about 0.1 grams per liter. The bath has a temperature of about 72° C. and a pH of about 8.1. The gaps having widths of at least one micron remain essentially free of extraneous plating.

Growth of silver nanowires from solutions: A cyclic penta-twinned-crystal growth mechanism

Abstract: Silver nanowires are synthesized by simple reduction of the silver ions with reductants such as glucose, sodium citrate, and sodium hypophosphite, etc., in the absence of the so-called surfactants or capping reagents at the temperature from 80 to 200 °C. Regardless of the reductants, the nanowires prepared at a given temperature are uniform in diameters, ranging from 30 to 50 nm at 100 °C. Nanoparticles coexist with nanowires in the products with larger diameters (usually larger than 50 nm). We find that all the silver nanowires in the as-prepared products are of cyclic penta-twinned structure, where five crystallites bond by the {111} facets. We propose that the intrinsic factor of the cyclic penta-twinned structure, i.e., the angular mismatch of the five crystallites in forming a gapless rod, controls the size of the nanowires and guides the directional growth of the nanowires with {110} as the active facets. The nanoparticles in the products are aggregates of imperfect penta-twinned crystals, which inh...