Abstract: A cathode arc source comprises: a cathode target; a first magnetic field source located above the target; a second magnetic field source located below the target; and a third magnetic field source located between the first and second magnetic field sources and having an opposite polarity to the first magnetic field source; wherein the resultant magnetic field from the first, second and third magnetic field sources has zero field strength in a direction substantially normal to the target at a position above the target. The invention also provides methods of striking a cathode target and methods of depositing coatings which can be carried out using the cathode arc source described herein.

Abstract: An electrode for electrochemical applications is coated with a layer of a-C, wherein the layer of a-C comprises at least 10 each of first and second sub-layers, being—(i) first sub-layers having high conductivity with a sp2 content of 60-95%, alternating with—(ii) second sub-layers having high corrosion resistance with a sp2 content of 50-90%, wherein the sp2 content of the first sub-layers is at least 3% greater than the sp2 content of the second sub-layers. A method of making such electrodes comprises: —a) depositing a first sub-layer comprising a-C, —b) depositing a second sub-layer comprising a-C wherein the sp2 content of the first sub-layer is at least 3% greater than the sp2 content of the second sub-layer, and—c) repeating the steps above to deposit at least 10 first sub-layers alternating with 10 second sub-layers, so as to produce the electrodes.

Abstract: A filter (104a, 104b, 108) for a cathode arc source comprises: a filter duct having at least one bend (104a, 104b), and a first magnetic field source for steering plasma through the filter duct for removal of macroparticles from the plasma; wherein the apparatus comprises a second magnetic field source (108) which is rotatably mounted surrounding a portion of the filter duct. Cathode arc sources (102) and cathode arc deposition apparatuses (106) comprise the filters described herein, and methods of filtering macroparticles from a beam of plasma emitted from a cathode arc source use the filters.

Abstract: A bipolar plate for a PEM hydrogen fuel cell is coated with a carbon-containing coating, the carbon-containing coating comprising in order: a) a titanium seed layer; b) a titanium nitride interfacial layer; and c) a a-C top layer, and wherein the bipolar plate is formed from stainless steel. Methods for making such coated plates are described. The a-C has a density of greater than 2.0 g/cm3, a molar hydrogen content of 5% or less, an sp2 carbon content of 40% to 80% and an sp3 carbon content of 20% to 60%. The coated plates possess good electrical conductivity and are resistant to corrosion.

Abstract: A substrate is coated with a multi-layer coating, comprising in order: (i) a first functional layer comprising ta-C, (ii) a second functional layer comprising ta-C, (iii) (a) a third functional layer comprising ta-C and a first intermediate layer comprising a carbide of a first element, or (b) a first intermediate layer comprising a carbide of a first element, and a second intermediate layer comprising the first element, wherein the ta-C has a hydrogen content less than 10% and an sp2 content less than 30%; wherein (i) the Young's modulus or (ii) the hardness or (iii) both the Young's modulus and the hardness independently stay the same or increase from layer to layer in (iii) (a) from the first intermediate layer to the first functional layer, or in (iii) (b) from the second intermediate layer to the first functional layer.

Abstract: A bipolar plate for a PEM hydrogen fuel cell is coated with a carbon-containing coating, the carbon-containing coating comprising in order: a) a titanium seed layer; b) a titanium nitride interfacial layer; and c) a a-C top layer, and wherein the bipolar plate is formed from stainless steel. Methods for making such coated plates are described. The a-C has a density of greater than 2.0 g/cm3, a molar hydrogen content of 5% or less, an sp2 carbon content of 40% to 80% and an sp3 carbon content of 20% to 60%. The coated plates possess good electrical conductivity and are resistant to corrosion.

Abstract: A filter (104a, 104b, 108) for a cathode arc source comprises: a filter duct having at least one bend (104a, 104b), and a first magnetic field source for steering plasma through the filter duct for removal of macroparticles from the plasma; wherein the apparatus comprises a second magnetic field source (108) which is rotatably mounted surrounding a portion of the filter duct. Cathode arc sources (102) and cathode arc deposition apparatuses (106) comprise the filters described herein, and methods of filtering macroparticles from a beam of plasma emitted from a cathode arc source use the filters.

Abstract: A method of depositing a coating on a substrate comprises simultaneously depositing a first material via a CVA process and a second material via a sputtering process; also described are coatings obtained therefrom and coated substrates.

Abstract: A cathode arc source comprises: a cathode target; a first magnetic field source located above the target; a second magnetic field source located below the target; and a third magnetic field source located between the first and second magnetic field sources and having an opposite polarity to the first magnetic field source; wherein the resultant magnetic field from the first, second and third magnetic field sources has zero field strength in a direction substantially normal to the target at a position above the target. The invention also provides methods of striking a cathode target and methods of depositing coatings which can be carried out using the cathode arc source described herein.

Abstract: The invention provides substrates with a multi-layer coating, comprising in order: i) the substrate; ii) a seed layer; ill) a barrier layer deposited via a CVD method; and iv) a functional layer deposited via a PVD method, and methods of making such coatings. The coatings of the invention have been shown to possess good resistance to corrosion.

Abstract: A substrate is coated with a multi-layer coating, comprising in order: (i) a first functional layer comprising ta-C, (ii) a second functional layer comprising ta-C, (iii) (a) a third functional layer comprising ta-C and a first intermediate layer comprising a carbide of a first element, or (b) a first intermediate layer comprising a carbide of a first element, and a second intermediate layer comprising the first element, wherein the ta-C has a hydrogen content less than 10% and an sp2 content less than 30%; wherein (i) the Young's modulus or (ii) the hardness or (iii) both the Young's modulus and the hardness independently stay the same or increase from layer to layer in (iii) (a) from the first intermediate layer to the first functional layer, or in (iii) (b) from the second intermediate layer to the first functional layer.

Abstract: The invention provides a substrate coated with a multi-layer coating, comprising in order: (a) the substrate; (b) a thermally insulating layer (e.g. Si3N4); (c) an interfacial layer (e.g. SiC); and (d) one or more layers comprising ta-C; wherein the interfacial layer promotes adhesion of the one or more layers comprising ta-C to the thermally insulating layer; and methods for producing such coatings.

Abstract: A method of continuously depositing a coating on a substrate comprises (a) depositing a first layer of ta-C on a substrate via a CVA process, said first layer having a first hardness and a first thickness of 100 mm or greater; (b) adjusting the parameters of the CVA process and depositing a second layer of ta-C on a substrate via a CVA process, said second layer having a second hardness and a second thickness of 10 mm or less, and (c) repeating the above steps to provide a coating comprising at least 5 such first layers and at least 4 such second layers, wherein the first thickness is greater than the second thickness and the first hardness is greater than the second hardness.