1. A method of preparation of ceramics based on lanthanum-doped barium titanate comprising the following steps:
(a) flash sintering of lanthanum-doped barium titanate powder, at a temperature between 950\xb0 C. and 1050\xb0 C., for a period of time between 1 min and 10 min, at a pressure of at least 50 MPa,
(b) heat treatment of the material thus obtained, at a temperature between 800\xb0 C. and 900\xb0 C., for a period of time between 2 h and 24 h, in an atmosphere of air or in an oxidizing atmosphere.
2. The method of preparation according to claim 1, wherein the step (a) is carried out at a temperature of 1050\xb0 C. for 3 minutes with a current of 370 A.
3. The method of preparation according to claim 1, wherein the sintering temperature in step (a) is reached using a temperature ramp of 50\xb0 C. per minute, starting at room temperature.
4. The method of preparation according to claim 1, wherein the step (b) is carried out at a temperature of 850\xb0 C., for 2 hours, in an atmosphere of air.
5. The method of preparation according to claim 1, wherein the lanthanum-doped barium titanate powder has the formula LaxBa(1-x)Ti(1-x4)O3, wherein x=0.048.
6. The method of preparation according to claim 1, wherein the lanthanum-doped barium titanate powder is synthesized by soft chemistry.
7. The method of preparation according to claim 6, wherein the lanthanum-doped barium titanate powder is obtained by:
coprecipitating TiCl3 and BaCl2,2H2O with LaCl3,7H2O in the presence of an ethanolic solution of oxalic acid for 5 h 30 min, then
calcining at 850\xb0 C.
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. Will increase safety in automobile traffic by giving the drivers a better view of any vehicle or other obstruction in the present side miror \u2018blind areas\u2019 of the basic vehicle withput diverting the drever’s attention from possible obstructions to the front of the vehicle
2 Will ease the tension on the drivers by giving himher a quick view of any vehicles coming up beside hisher vehicle without the need to look back over the driver’s shouolder thus diverting the driver’s atention from the front view of the driver
3. Relieve the driver of the need to divert hisher attention from the front to the side to determine of any vehicle is beside himher in the blind spot of current mirrors