1. A capacitor comprising:
a dielectric film; and
a first electrode and second electrode formed sandwiching said dielectric film and facing each other,
wherein said dielectric film has a density exceeding 72% of the theoretical density calculated based on the lattice constant,
wherein either or both of said first electrode and said second electrode contain at least one metal selected from the group consisting of Cu, Ni, Al, stainless steel and a nickel-based alloy, and
wherein said dielectric film comprises particles with a mean particle size of more than 40 nm and less than or equal to 70 nm.
2. A capacitor according to claim 1,
wherein said dielectric film contains at least one compound selected from the group consisting of barium titanate, strontium titanate and barium strontium titanate.
3. A capacitor according to claim 1, wherein the dielectric film has a dielectric constant of from 900 to 2463.
4. A capacitor according to claim 1, wherein the dielectric film comprises particles with a mean particle size of more than 40 nm and less than or equal to 50 nm.
5. A capacitor according to claim 4, wherein the dielectric film has a dielectric constant of from 900 to 2206.
6. A dielectric film production process which comprises:
a precursor layer-forming step in which a precursor layer containing a dielectric material is formed on a metal layer; and
an annealing step in which said precursor layer is heated for crystallization of said dielectric material in said precursor layer to form a dielectric film,
wherein during at least part of said annealing step, said precursor layer is heated to 550 to 1000\xb0 C. in a reduced pressure atmosphere with a pressure of 1\xd710\u22129 to 1\xd7103 Pa as measured with an ionization vacuum gage,
wherein the dielectric film has a density exceeding 72% of the theoretical density calculated based on the lattice constant, and
wherein the dielectric film comprises particles with a mean particle size of more than 40 nm and less than or equal to 70 nm.
7. A dielectric film production process according to claim 6,
wherein said metal layer includes at least one metal selected from the group consisting of Cu, Ni, Al, stainless steel and a nickel-based alloy.
8. A dielectric film production process according to claim 6,
wherein said metal layer comprises Cu,
and said precursor layer is heated in said annealing step in a reduced pressure atmosphere with a pressure of 4\xd710\u22121 to 8\xd710\u22121 Pa as measured with an ionization vacuum gage.
9. A dielectric film production process according to claim 6,
wherein said metal layer comprises Ni,
and said precursor layer is heated in said annealing step in a reduced pressure atmosphere with a pressure of 2\xd710\u22123 to 8\xd710\u22121 Pa as measured with an ionization vacuum gage.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Bypass turbine engine (1), in particular for an aircraft, in which air flows circulate from upstream to downstream, the turbine engine (1) extending axially and comprising:
an inner casing (11), an inter-duct casing (12) and an outer casing (13) so as to define a primary duct (V1) between the inter-duct casing (12) and the inner casing (11), and a secondary duct (V2) between the inter-duct casing (12) and the outer casing (13),
a rotary shaft (BP) comprising, at the upstream end, a movable fan (2) comprising radial blades (20) of which the free ends face the outer casing (13) of the turbine engine so as to compress an air flow at least in the secondary duct (V2),
said turbine engine (1) is characterised in that it comprises
a plurality of variable-pitch radial stator vanes (5) mounted upstream of the movable fan (2), said variable-pitch vanes being configured to deflect the axial incident air (F) and the movable fan being configured to axially rectify said deflected air into the secondary duct (V2), and
means for individually adjusting the pitch of the variable-pitch radial vanes (5) so as to allow an adaptive pitch to be provided depending on the configuration of the turbine engine.
2. Turbine engine according to claim 1, wherein the means for individually adjusting the pitch of the radial vanes (5) comprise a single control ring (24) and rods (25, 30) for connecting said control ring (24) to each of said radial vanes (5).
3. Turbine engine according to claim 1, wherein the inner casing (11), the inter-duct casing (12) and the outer casing (13) are at a radial distance from one another in the turbine engine (1) so as to define a turbine engine (1) having a bypass ratio (BPR) that is greater than or equal to 15.
4. Turbine engine according to claim 1, wherein the rotational speed of the free ends of the blades (20) of the movable fan (2) is less than 340 ms.
5. Turbine engine according to claim 1, wherein the plurality of variable-pitch radial vanes (5) extend in the same plane which is transverse to the axis of the turbine engine (1).
6. Turbine engine according to claim 1, wherein the axial distance between the plurality of variable-pitch radial vanes (5) and the movable fan (2) is between 0.1 and 10 times the mean chord of a variable-pitch radial vane (5).
7. Turbine engine according to claim 1, wherein the blades (20) of the movable fan (2) extend between the inner casing (11) and the outer casing (13) of the turbine engine (1).
8. Turbine engine according to claim 1, wherein each variable-pitch radial vane (5) has an aerodynamic profile so as to accelerate the incident air flow in accordance with a laminar flow.
9. Turbine engine according to claim 1, wherein each variable-pitch radial vane (5) has a body which is movable in rotation about a radial axis.
10. Turbine engine according to claim 1, wherein each variable-pitch radial vane (5\u2032) has a fixed body (50\u2032) and a movable flap (51\u2032).
11. Turbine engine according to claim 1, wherein each variable-pitch radial vane (5) is configured to ensure an air-brake function in a given pitch position.
12. Turbine engine according to claim 2, wherein the control ring (24) is movably mounted in rotation about a longitudinal axis (X-X) of the turbine engine, on a fixed casing (13, 21) which extends radially on the inside or on the outside of the radial vanes (5).
13. Turbine engine according to claim 12, wherein the adjustment means are mounted on the fixed casing (13, 21) and comprise, for each radial vane (5):
a first connecting rod (25) which is movably mounted in rotation about a first substantially radial pivot pin (29), which is mounted on the control ring (24), and about a second substantially radial pivot pin (27), which is mounted on the fixed casing (13, 21), and
a second connecting rod (30) which is pivotally mounted about a third substantially radial pivot pin (33), which is connected to the vane (5) and offset along the longitudinal axis (X-X) in relation to a pitch pin (23) of said radial vane (5),
the second connecting rod (30) being articulated to the first connecting rod (25) so as to be able to pivot about a substantially radial hinge pin (31) which is at a distance from the second pivot pin (27).
14. Turbine engine according to claim 13, wherein said second connecting rod (30) comprises means for modifying a first distance (d1), between the third pivot pin (33) and said hinge pin (31).
15. Turbine engine according to claim 13, wherein the hinge pin (31) is connected to the first connecting rod (25) by connection means (32) which are configured so as to be able to modify a second distance (d2), between said hinge pin (31) and the second pivot pin (27).
16. Turbine engine according to claim 13, wherein at least one of the parameters selected from a first distance (d1), between the third pivot pin (33) and said hinge pin (31), and a second distance (d2), between said hinge pin (31) and the second pivot pin (27), is different between at least two radial vanes (5).
17. Turbine engine according to claim 13, wherein, for each radial vane (5), the second pivot pin (27) and the pitch pin (23) of said vane are located on the same side relative to the second connecting rod (30), in the direction of the longitudinal axis (X-X) of the turbine engine.
18. Turbine engine according to claim 17, wherein the first pivot pin (29) is located on the opposite side relative to the second connecting rod (30), in the direction of the longitudinal axis (X-X) of the turbine engine.
19. Turbine engine according to claim 13, wherein the second connecting rod (30) is substantially perpendicular to the first connecting rod (25) for at least one position of the control ring (24).
20. Method for adjusting the pitch of radial stator vanes of a turbine engine according to claim 13, when carrying out a maintenance operation or an adjustment of the turbine engine, comprising a step a) consisting in modifying, for at least one vane (5), a first distance (d1), between the third pivot pin (33) and said hinge pin (31).
21. Method according to claim 20, comprising a step b) consisting in modifying, for at least one vane (5), a second distance (d2), between said hinge pin (31) and the second pivot pin (27).
22. Method according to claim 21, wherein, a first position (Ga1) and a second position (Ga2) of the control ring (24) being defined so as to correspond to a first (\u03b81) and a second (\u03b82) pitch angle of each vane (5), as a result of operating conditions of said turbine engine, a preliminary step consists in defining, for each vane (5), the values of said first (d1) and second (d2) distances, making it possible to obtain the first (\u03b81) and second (\u03b82) pitch angles respectively for the first (Ga1) and second (Ga2) positions of the control ring (24), said method then comprising for each vane (5) a step a) and a step b) using the values defined in the preliminary step.