Crystallization Behaviour of Thin NiP Alloy Films Prepared by Electroless or Galvanic Deposition

Abstract

Structure and crystallization behaviour'of thin Niloo-zP, (7 5 x < 32) alloy films, prepared by electroless and by galvanic deposition is studied by electron diffraction. Their properties depend strongly on the metal substrate. Alloys with an intermediate P content show a strong composition gradient in the vicinity of the alloy substrate interface. However, the results of the diffraction studies indicate that the crystallization behaviour is only determined by the mean composition of the alloy films. For the higher concentration regime (x > 25) final crystallization products are Ni,,P, + Ni,P (25 < x < 29.4) and Ni,,P, + Ni,P (29.4 < x < 33.3), respectively. Struktur und Kristallisationsverhalten dunner, galvanisch und stromlos abgeschiedener N i m -$P, (7 5 x < 32) Legierungsschichten werden mit Hilfe der Elektronenbeugung untersucht. Ihre Eigenschaften hingen stark von der Natur des Metallsubstrats ab. Legierungen mit mittlerem P-Gehalt zeigen einen ausgepriigten Konzentrationsgradienten in der Nachbarschaft der Legierungs-Substrat-Grenzfliiche. Hingegen ergeben die Beugungsuntersuchungen, daB das Kristallisationsverhalten allein durch die mittlere Zusammensetzung der Legierungsschichten bestimmt wird. Im Bereich hoherer P-Konzentrationen (z > 25) sind Ni12P5 + Ni,P (25 < x < 29,4), bzw. Ni,,P, + Ni,P (29,4 < z < 33,3) die endgultigen Kristallisationsprodukte. 1) Petersenstr. 20, D-6100 Darmstadt, FRG. 2) Part of Dissertation, D17, TH Darmstadt, 1985. 9' 132 U. PITTERMANN and S. RIPPER

Structure and Crystallization of Nickel‐Phosphorus Alloys Prepared by High‐Rate Electrodeposition

“…Phase transformation of alloys.--Phase transformation of the metastable nickel-phosphorus deposits were characterized by the combination of calorimetry and x-ray diffractometry. The crystallization of amorphous Ni-P alloys has been known to proceed through several metastable phases before reaching the final equilibrium phases (14,20). These intermediate phases can be quite different in structure, depending on the phosphorus content.…”

“…Calorimetry shows a transition around 300~ the enthalpy of which is proportional to the percent contained phosphorus (13). Two careful studies (12,14) of the recrystallization of amorphous nickel-phosphorus alloy indicate that below the crystallization temperature, nickel crystals precipitate to a relatively small extent. At the crystallization temperature, crystals of Ni3P grow at the expense of the fcc Ni phase.…”

Amorphous Nickel Phosphide Alloy Coatings Obtained by Magnetron Sputtering Methods for Magnetic Recording Disk

“…Low P content alloys are supersaturated solutions of P dissolved in fcc Ni, and the grain size decreases and the strain increases with increasing P content (6,7). Low P content alloys are supersaturated solutions of P dissolved in fcc Ni, and the grain size decreases and the strain increases with increasing P content (6,7).…”

“…A nickel-phosphorus alloy can be prepared in the crystalline or amorphous state, depending on the phosphorus content. Low P content alloys are supersaturated solutions of P dissolved in fcc Ni, and the grain size decreases and the strain increases with increasing P content (6,7). A higher content of P tends to stabilize the amorphous phase in the Ni-P system.…”

Propiedades asociadas a la estructura local en sistemas nanométricos: estudio mediante el empleo de técnicas basadas en el uso de luz de sincrotrón

“…La estructura y la química del Ni 5 P 2 no son totalmente conocidas. Se ha confirmado su presencia por difracción de rayos X (Nowotny & Henglein 1938) y más tarde se observó que la fase Ni 5 P 2 resulta metaestable y termina descomponiéndose en las fases Ni 3 P y Ni 12 P 5 (Pittermann & Ripper 1986).…”