Ni-P Layer Research Articles

Application of “diamond polymer” films in hard disk technology

Diamond polymer films (DPFs) are produced by plasma polymerization of silicon organic agents. A special plasmatron construction allows direct injection of a high boiling liquid agent in an active plasma, its evaporation and ionization in the thin boundary layer of the injector head. and autonomic control of the plasma parameters and the substrate potential (0.5–5.0 KeV, 1.76 MHz). The DPFs with 25–60 nm thickness were used for the protection of ferromagnetic coatings and different thin film magnetic 5 1 4 in disks. In all cases the disks have exhibited very high wear resistance. Self-lubrication effects were observed. The development of thick DPFs (1–5 μm) as an alternative to NiP layers is in the laboratory stage at the moment. Our seven-year experience of using DPFs in hard disk technology is discussed.

Influence of sol-gel SiO2/TiO2 protective coatings on the optical and thermal properties of nickel-phosphorus selective surfaces

A sol-gel coating was applied to an electroless acid-etched Ni-P spectrally selective surface in order to investigate its influence on the optical and thermal properties of the selective surface. The sol-gel process is a low-temperature preparation of glasses, which is of interest considering the lack of resistance of selective surfaces at the high temperatures generally needed to prepare glasses by the melting technique. The application of a glass coating on the Ni-P layer increases its oxidation resistance at high temperatures and improves the optical and thermal properties of this selective surface for heat treatments in air, up to 400 °C.

Effect of ferromagnetic NiP on the properties of longitudinal recording media

The nonferromagnetic NiP layer which is deposited by electroless plating, provides a coating for the aluminum substrate to provide an extremely smooth and defect free substrate for rigid memory disks. The paper presents results of the magnetic properties of the NiP layer exposed to high temperatures. Both H c and M s changed with annealing time and temperature. The associated phase transformation were studied using X-ray diffraction and SEM. Our results showed that at an annealing temperature of 300–400° C the transformation was associated with the precipitation of Ni 3P. However, at relatively higher annealing temperature; e.g. 500° C, Ni 5P 2 precipitates were also observed. The paper also discusses the effect of ferromagnetic NiP layer on the recording properties of Co-15 at% Cr/Cr longitudinal media. Our results showed that there was a significant interaction between the ferromagnetic NiP layer and the magnetic Co-Cr film which resulted into an increased media noise in the low frequency range (<2 MHz) and a modulation noise “skirts” around the signal. As a result, the integrated media noise increased and thus, caused a 2 dB loss in SNR.

Magnetic properties and media noise of Co-Ni-P plated disks

Magnetic properties and read-write characteristics of Co-Ni-P plated disks are examined. In-plane coercive force and squareness increase with increasing the thickness of an Ni-P layer which is formed between the substrate layer (Cu-Sn) and Co-Ni-P film. However, media noise increases with thickening of the Ni-P layer. The relationships between magnetic properties and media noise are investigated by measuring rotational hysteresis (Wr) and its integral (RH). As a result, it is found that media noise closely correlates RH values: smaller RH values cause less media noise. This result shows that media noise is dominated by the magnetization process, and magnetic thin film in which the magnetization process occurs through coherent rotation is desirable for magnetic recording media.

Recording characteristics of electroless-plated perpendicular media for flexible disks

The read/write characteristics of electroless-plated perpendicular magnetic recording media for flexible disks were studied using commercial VHS and 8-mm VTR ring heads. Excellent results were shown for a medium composed of Co-Ni-Re-P plated on a non-magnetic electroless-plated Ni-P layer. A Ni-P underlayer of only 500 A greatly improved the read/write characteristics of the disk. Reproduced signals over 300 kFRPI were observed for a system using a VHS head, and D_{50} = 134 kFRPI was obtained using an 8-mm head.

Friction and wear of amorphous Ni-B, Ni-P films obtained by ion implantation into nickel

The wear and friction resistance of nickel surfaces implanted with increasing doses of boron or phosphorous was investigated, with a pin-on-disc geometry and a 100C6 steel rider, in air. The seizure resistance is drastically improved when the implanted dose is sufficiently high to give an amorphous Ni-B or Ni-P layer.

The process of formation of amorphous Ni-P layers made by electroless deposition

The composition, electronic states and structure of thin Ni-P layers deposited by the electroless method were studied by soft X-ray emission spectroscopy, differential thermal analysis, secondary ion emission, X-ray diffraction and auxiliary microscopic investigations. The first centres of the layer consisted of pure crystalline nickel nuclei. With increasing growth, the deviation from crystallinity increased, with continous changes in the composition. Also, diffusion processes take place transporting aluminium and silicon from the underlying substrate.

Pretreatment of Al-Mg alloys for electrodeposition by immersion zinc and electroless nickel

Electron microscopy and X-ray methods were used to investigate the various stages of zincate treatment and electroless Ni-P deposition upon Al-Mg (4 wt.% Mg). It is shown that the roughening of the surface of the alloy during this treatment enhances the attachment of the Ni-P coating. No evidence was found within the sensitivity of the applied methods that new phases which could influence adhesion are formed during the annealing at 180 °C at the Al-(Ni-P) interface. It is proved that annealing affects the desorption of hydrogen included in the Ni-P layer durings its formation. Therefore annealing may be substituted by an adequate pause before the next coating is deposited.

Electroless NiP processing for hybrid integrated circuits

Electroless methods for depositing conductive layers on insulating materials can be used in producing hybrid integrated circuits (HIC's), as alternatives to the evaporation and sputter deposition techniques. Compared with these techniques, electroless procedures are in general relatively simple and it is easy to metallize holes in substrates. Further, electroless deposited NiP layers can be used for the integration of resistors. An electroless procedure will be described for metallizing alumina and fused quartz substrates, and further a method for producing resistive layers suitable for integrated resistors. After electroless plating the desired conductive patterns are obtained by localized electroplating with gold and etching away the unwanted parts of the NiP layer. Some properties of the conductive patterns obtained in this manner have been investigated, for instance: the adhesion between the metallic pattern and substrate, microwave losses in microstrip configuration, geometrical accuracies and performance of the resistive layers. A short description of the test methods applied will be given and the results discussed. Many hybrid integrated circuits for use at frequencies up to 22 GHz already have been made by using electroless procedures.

A highly reliable plated wire: Study on corrosion of magnetic films

Corrosion of magnetic films greatly affects the reliability of plated-wire memories. In plated films, additives in plating baths are codeposited onto films and affect the electrochemical state of the films. In this connection, a study was undertaken on the effects of thiourea and saccharin on corrosion. From current-potential curves and environmental tests it was found that the film deposited in a thiourea bath was easier to corrode than the film obtained from a saccharin bath. To protect the film from corrosion, a coating of Ni-P was made on it. This Ni-P coating was effective as an anticorrosive layer, but not to the required extent. Again when the wire was coated with a polyparaxylylen polymer on top of the Ni-P layer, no corrosion was found to occur. Moreover, no failure bit occurred from among the 6 × 104bits during the test of 30 cycles of MIL-STD-202D-106C.

Influence of intermediate layers on coercive force of laminated Co-P films

This paper investigated the coercive force (H c ) of laminated Co-P films. The films were laminated by introducing intermediate layers of Pd ( T \sim 25 A) or nonmagnetic Ni-P (T = 250 A) between the Co-P films. The thickness of the Co-P films was varied from 650 A to 2600 A but was maintained constant within any series of laminations. The H c was evaluated as a function of total thickness for multiple Co-P laminate thicknesses up to 10,000 A. The H c of laminated Co-P films with intermediate Pd layers increased with total lamination thickness regardless of the thickness of the individual Co-P film. However, Co-P laminates deposited from a dilute solution with intermediate layers of Ni-P exhibited H c values independent of the total lamination thickness. The H c was independent of the total lamination thickness regardless of the base material provided Ni-P was deposited as the substrate. The magnitude of the H c was dependent on the Co-P film thickness. The H c of such Co-P laminates can be adjusted from 340 Oe to 700 Oe by selection of the appropriate thickness of the Co-P film. Co-P laminates deposited from a concentrated solution with intermediate layers of Ni-P exhibit H c values which decrease with total lamination thickness. These films exhibited lower H c values than nonlaminated Co-P films.

Structure and properties of nickel-phosphorus coatings in relation to annealing temperature and time

1. With diffusion annealing, the structure of nickel-phosphorus coatings depends on their interaction with the steel substrate. A mechanism was proposed for the interaction of the two-phase nickel-phosphorus coating with the steel substrate, consisting of decomposition of nickel phosphides in the transition layer with diffusion of iron from the substrate into the coating, and formation of phosphides in the surface layers still not “diluted” with iron. 2. With an increase of annealing temperature and time the front of the phosphides is forced back to the surface layers of the coating, with simultaneous growth of the phosphorus-free layer. The reduction in the thickness of the phosphorus-containing layer ceases with formation of the single-phase Ni3P layer. 3. The thicknesses of the phosphorus-free and phosphorus-containing layers during annealing depend not only on the annealing parameters but also the original thickness of the coating. With decreasing thickness of the original coating the formation of the single-phase layer of nickel phosphide is completed in a shorter time. 4. The microhardness of the phosphorus-containing layer depends on the annealing parameters, the thickness of the original coating, and the development of precipitation hardening processes in it, softening due to coalescence, and subsequent hardening as the result of enrichment with phosphorus up until the formation of the single-phase layer. 5. At low temperatures and short annealing times the maximum microhardness of the phosphorus layer is reached due to precipitation hardening, while at high temperatures and long annealing times it is due to the increase in the phosphorus concentration. With decreasing thickness of the original coating the annealing time required to attain the maximum hardness as the result of enrichment with phosphorus is shorter.

Shaft seal for high rotational speeds: J Peresse, Jour Phys, 26(3), March 1965, 121A–122A

Electroless methods for depositing conductive layers on insulating materials can be used in producing hybrid integrated circuits (HIC's), as alternatives to the evaporation and sputter deposition techniques. Compared with these techniques, electroless procedures are in general relatively simple and it is easy to metallize holes in substrates. Further, electroless deposited NiP layers can be used for the integration of resistors.An electroless procedure will be described for metallizing alumina and fused quartz substrates, and further a method for producing resistive layers suitable for integrated resistors. After electroless plating the desired conductive patterns are obtained by localized electroplating with gold and etching away the unwanted parts of the NiP layer.Some properties of the conductive patterns obtained in this manner have been investigated, for instance: the adhesion between the metallic pattern and substrate, microwave losses in microstrip configuration, geometrical accuracies and performance of the resistive layers. A short description of the test methods applied will be given and the results discussed.Many hybrid integrated circuits for use at frequencies up to 22 GHz already have been made by using electroless procedures.

Vacuum chamber for the IP-4M test equipment: V A KonomenkoInd Lab, 30(10), published March 1965, 1562–1563. Translated from the Russian Zav Lab, 30(10), Oct 1964, 1263–1264.

Electroless methods for depositing conductive layers on insulating materials can be used in producing hybrid integrated circuits (HIC's), as alternatives to the evaporation and sputter deposition techniques. Compared with these techniques, electroless procedures are in general relatively simple and it is easy to metallize holes in substrates. Further, electroless deposited NiP layers can be used for the integration of resistors.An electroless procedure will be described for metallizing alumina and fused quartz substrates, and further a method for producing resistive layers suitable for integrated resistors. After electroless plating the desired conductive patterns are obtained by localized electroplating with gold and etching away the unwanted parts of the NiP layer.Some properties of the conductive patterns obtained in this manner have been investigated, for instance: the adhesion between the metallic pattern and substrate, microwave losses in microstrip configuration, geometrical accuracies and performance of the resistive layers. A short description of the test methods applied will be given and the results discussed.Many hybrid integrated circuits for use at frequencies up to 22 GHz already have been made by using electroless procedures.