Magnetoresistive sensor having a closed domain structure and electrode biasing

A magnetoelectric conversion element comprising:

• a magnetoresistive effect material having at least two sections adjacent to each other along the longitudinal direction of said magnetoresistive effect material to provide closed domain structures, respectively, each of the magnetoresistive effect material sections including first and second magnetic domains which have their directions of spontaneous magnetization reverse to each other in the longitudinal direction of said magnetoresistive material and third and fourth magnetic domains which are respectively positioned at opposite ends of said first and second magnetic domains to couple said first and second magnetic domains therethrough;
• a first contact for connection to a current source and formed on the third and fourth magnetic domains of and adjacent to each other between the adjacent magnetoresistive effect material sections;
• second and third contacts for connection to a current source and formed respectively on the fourth and third magnetic domains of and spaced from each other between the outer magnetoresistive effect material sections;
• and
• bias electrode means disposed on the magnetoresistive effect material sections, respectively, each of said bias electrode means including at least one first segment disposed on the first magnetic domain to extend in a first direction inclined with respect to the longitudinal direction of the magnetoresistive effect material and at least one second segment disposed on the second magnetic domain to extend in a second direction inclined with respect to the longitudinal direction of the magnetoresistive effect material but opposite to said first direction, thereby biasing the direction of current flow through the associated magnetoresistive effect material section between the contacts with respect to the longitudinal direction of the magnetoresistive effect material.

A magnetoelectric conversion element comprising:

• a magnetoresistive effect material having a closed domain structure including first and second magnetic domains which have their directions of spontaneous magnetization reverse to each other in the longitudinal direction of said magnetoresistive effect material and third and fourth magnetic domains which are respectively positioned at opposite ends of said first and second magnetic domains to magnetically couple said first and second magnetic domains therethrough, a groove being provided between said first and second magnetic domains along the longitudinal direction of said magnetoresistive effect material to extend across said fourth magnetic domain so that said groove is opened at one end of the longitudinal direction of said magnetoresistive effect material to separate said fourth magnetic domain into two parts;
• a connecting member of magnetic material formed through an electrically insulative member on and over both the two parts of said fourth magnetic domain separated by said groove;
• first and second contacts for connection to a current source and formed respectively on said first and second magnetic domains at the ends thereof near said fourth magnetic domain;
• a third contact formed on said third magnetic domain;
• and
• bias electrode means including at least one first segment disposed on said first magnetic domain to extend in a first direction inclined with respect to the longitudinal direction of said magnetoresistive effect material and at least one second segment disposed on said second magnetic domain to extend in a direction inclined with respect to the longitudinal direction of said magnetoresistive effect material but opposite to said first direction, thereby biasing the direction of current flow through said magnetoresistive effect material between the contacts with respect to the longitudinal direction of said magnetoresistive effect material.