Physical diamond-like carbon

After lapping, the sliders will be cleaned, and then a passivation film of diamond-like carbon (DLC) will be deposited on the surfaces of sliders through chemical vapor deposition (CVD) to protect the pole area from chemical-physical corrosion and electrostatic discharge attack. Corrosion in pole areas will result in loss of read/write functions. A corrosion test was taken to examine the ability of the sliders polished by different slurries as shown in Table 6. It can be seen that the MRR change rate of the sliders polished by UFD slurry is much less than that polished by the slurry T5qre III, that is, the capability of anti-corrosion of the former is much better than that of the latter. 

M.V. Geis, M.A. Tamor, Diamond and Diamond-like Carbon , in Encyclopedia of Applied Physics, Vol. 5, VCH Publishers, Veinheim (1993). 

Deposition from the gas phase can be performed by a wide variety of physical (PVD) and chemical (CVD) processes, with or without assistance of a plasma. These processes are particularly well suited for the fabrication of thin coatings of refractory materials such as carbides, nitrides, borides or diamond like carbon (DEC). The resulting coatings are useful for tribological and other functional applications, but they generally offer only a limited corrosion resistance. 

Amorphous carbon is a novel material with which to study defects and to understand the physics of disorder, which can be enhanced by ion irradiation [163], Ion implantation studies of different types of carbon at low energies (100 keV to 1 MeV) and high dosages (10 ions/cm ) attracted the attention of many scientists [164]. The role of the ion beam in low-energy ion implantation is to displace the carbon atoms and introduce disorder in the material. In diamond-like carbon films... 

Diamond coatings are also produced by physical vapor deposition (PVD). Such coatings however are a mixture of sp (graphite) and sp (dianrand) bonds and are considered a different material usually referred to as diamond-like carbon (DLC). They are reviewed in Ch. 14. 

Even though the existence of C3P4 was postulated together with C3N4 as early as in 1984 , no research has been done on carbon phosphide besides a recent work on phosphorus-doped diamond-like carbon films. The present study is therefore expected to provide basic information on the structure and properties of carbon phosphide. It is of interest to know whether C3P4 can form a stable alloy. And if it does, what is the possible structure What physical properties does it have The ultimate aim is to produce a stable form of carbon phosphide having potentially useful electronic properties. 

Diamond-like film or amorphous diamond is made up of sp and sp bonded carbon. The amount of sp bonds depends on the method of deposition and can be as high as 60%. The higher the number of sp bonds the harder the material, the higher the band-gap, and the better the overall physical properties of the material. 

Altogether the thermal transformation of nanodiamond turned out a suitable method to prepare macroscopic amounts of onion-like carbon. It is true that the products obtained are inhomogeneous to some extent and that the resulting onions show various deficiencies (defects, deviations from spherical shape), but still the heating of diamond in vacuo constitutes the best method to date to generate larger amounts of carbon onions and study in principle their physical and chemical properties. 

Lavoisier s earliest studies showed a respect for precise measurement. He demonstrated that diamonds decompose in strong heat (Boyle had proven this a century earlier) but showed that air was necessary and that the decomposition product turned lime water milky and was thus fixed air (CO ). In 1772 his studies extended to the combustion of phosphorus and sulfur, which, like carbon, produced acid airs that weighed more than the solids that produced them. Similarly, he verified the observation by Jean Rey in 1630, also noted by Boyle and others, that the calxes formed hy heating metals were heavier than the metals themselves. In his first great book (Opuscules Chimiques et Physiques, Paris, 1774 Essays Physical and Chemical, London, 1776), Lavoisier first offered the idea that these processes involved absorption of some elastic fluid present in air rather than loss of phlogiston to the air. In this hook he confused this elastic fluid with fixed air. ... 

Another piece of big news for the inorganic chemist in the late 1900s turned out to be big news for organic, physical, analytical, and biochemists, too. This was the discovery of a third solid form of carbon— the other two being diamond and carbon. This one forms a sphere shaped like the geodesic dome structure designed by the U.S. philosopher and engineer R. Buckminster Fuller it is named appropriately buckminsterfullerene. 

Kuznetsov, V. L., Chuvilin, A. L., Butenko, Y, V, Mal kov, I. Y. and Titov, V. M., Onion-like carbon from ultra-disperse diamond. Chemical Physics Letters, 222, 1994, 343-348. 

Hiraki, J., Mori, H., Taguchi, E., Yasuda, H., Kinoshita, H. and Ohmae, N., Transformation of diamond nanoparticles into onion-like carbon by electron irradiation studied directly inside an ultra-high vacuum transmision electron microscope. Applied Physics letters, 86,2005,223101. 

It turned out that the admixture of sp2-carbon exerts a decisive effect on the electrode quality of diamond films. And yet, modern physical and optical experimental techniques, like Raman and Auger spectroscopy, AFM, etc., failed in the elucidation of subtle effects exerted by the admixture of non-diamond carbon on the behavior of polycrystalline diamond films it is the electrochemical measurements that give plausible information [22] (see Section 6.3). 

Although the silicon atom has the same outer electronic structure as carbon its chemistry shows very little resemblance to that of carbon. It is true that elementary silicon has the same crystal structure as one of the forms of carbon (diamond) and that some of its simpler compounds have formulae like those of carbon compounds, but there is seldom much similarity in chemical or physical properties. Since it is more electro-positive than carbon it forms compounds with many metals which have typical alloy structures (see the silicides, p. 789) and some of these have the same structures as the corresponding borides. In fact, silicon in many ways resembles boron more closely than carbon, though the formulae of the compounds are usually quite different. Some of these resemblances are mentioned at the beginning of the next chapter. Silicides have few properties in common with carbides but many with borides, for example, the formation of extended networks of linked Si (B) atoms, though on the other hand few silicides are actually isostructural with borides because Si is appreciably larger than B and does not form some of the polyhedral complexes which are peculiar to boron and are one of the least understood features of boron chemistry. 

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