Device consisting of various thin films and use of such a device
View Patent ↗A device comprising: an assembly consisting of two, respectively upper and lower thin layers each forming a ferromagnetic element and separated by a thin layer forming a non magnetic element, said assembly being made up so that the layers forming the ferromagnetic elements are magnetically coupled through the layer forming a non magnetic element; an electrode, a layer forming a ferroelectric element in which the polarization may be oriented in several directions by applying an electric voltage through said layer, said layer forming a ferroelectric element being positioned between the layer forming a lower ferromagnetic element and the electrode; said device being configured so as to allow control of the magnetic configuration of the layers forming ferromagnetic elements by the direction of the polarization in the layer forming a ferroelectric element.
1. A device comprising:
an assembly consisting of two thin respectively upper and lower layers, each forming a ferromagnetic element and separated from one another by a thin layer forming a non magnetic element, said assembly being made up so that the layers forming the ferromagnetic elements are magnetically coupled through the layer forming a non magnetic element;
an electrode,
a layer forming a ferroelectric element in which the polarization may be oriented in several directions by applying an electric voltage through said layer, said layer forming a ferroelectric element being positioned between the layer forming a lower ferromagnetic element and the electrode;
said device being configured so as to allow control of the magnetic configuration of the layers forming ferromagnetic elements by the direction of the polarization in the layer forming a ferroelectric element, the magnetic coupling between the lower layer forming a ferromagnetic element and the layer forming a ferroelectric element not being influenced by the direction of the polarization in the layer forming a ferroelectric element.
2. The device according to claim 1 , wherein the layer forming a non magnetic element has a thickness comprised between 0.2 and 10 nm.
3. The device according to claim 1 wherein the layer forming a ferroelectric element has a thickness comprised between 0.2 and 500 nm.
4. The device according to claim 1 wherein it comprises a system giving the possibility of setting the magnetization of a ferromagnetic material.
5. The device according to claim 4 , wherein said system consists of a layer of small thickness formed with an antiferromagnetic material.
6. The device according to claim 4 , wherein:
the electrode is formed with a ferromagnetic material;
the layer forming a ferroelectric element is adapted to let through a tunnel current between the ferromagnetic electrode and the lower layer forming ferromagnetic element, said layer preferably having a thickness comprised between 0.2 and 10 nm;
said system with which the magnetization of a ferromagnetic material may be set, is adapted for setting the magnetization of the upper layer forming a ferromagnetic element and that of the ferromagnetic electrode.
7. The device according to claim 1 , wherein the layer forming a non magnetic element is conductive, said device being adapted so as to generate a dipolar magnetic field which depends on the magnetic configuration of the layers forming lower and upper ferromagnetic elements and which may be combined in the form of lines or networks for allowing generation and electric control of a magnetic field landscape.
8. The use of a device according to claim 1 , in a three terminal magnetic memory in which the magnetic information is written by applying an electric field applied through the ferroelectric element.
9. The use of a device according to claim 6 in a two terminal magnetic memory, in which the magnetic information is written by applying an electric field applied through the ferroelectric element.
10. The use of at least one device according to claim 7 in a system adapted for magnetic recording.