Method for producing a permanent or soft magnet

A method for producing a permanent or soft magnet, wherein it comprises at least the following steps:

• a) providing:
• a solution containing at least one solvent in which are dispersed a set of objects which possess a permanent magnetic moment;
• a substrate;
• and
• at least one 1st pad and one 2nd pad fixed to a surface of the substrate or provided within a cavity in the substrate, wherein the at least one 1st pad and one 2nd pad are made of a ferromagnetic material, said 1st pad includes a face facing a face which the 2nd pad includes, said facing faces being mutually parallel;
• b) depositing the solution on the surface of the substrate or, if the at least one 1st pad and one 2nd pad are provided within a cavity in the substrate, within the cavity, so that the 1st and 2nd pads are at least partly immersed in said solution;
• c) placing the substrate in an external magnetic field oriented in a direction perpendicular to the faces of the 1st pad and of the 2nd pad which are facing and parallel to each other so that at least part of the set of objects are grouped together between said face of the 1st pad and said face of the 2nd pad which are facing and parallel to each other and that each of the objects of the at least part of the set of objects are oriented in a same direction as the direction of the applied external magnetic field, so as to form a permanent or soft magnet;
• d) optionally, at least one washing of the substrate is carried out with at least one solvent;
• e) totally or partially evaporating the at least one dispersion solvent from the set of objects and from the at least one washing solvent if present,
• wherein the external magnetic field magnetizes the pads and the magnetized pads create magnetic field gradients leading to an attraction zone between the 1st pad and the 2nd pad.