Ultrahigh tunnel magnetoresistance using an artificial superlattice barrier with copper and aluminum oxide

Nanoelectronics group, Department of Engineering Science and Ocean Engineering National Taiwan University 1, Sec. 4, Roosevelt Road, Taipei, 10660, Taiwan

^(a) hsuehwj@ntu.edu.tw

Received: 10 March 2015
Accepted: 17 August 2015

Abstract

This paper proposes an ultrahigh tunnel magnetoresistance that is achieved by a magnetic tunnel junction with an artificial superlattice barrier that is composed of alternate layers of copper and aluminium oxide. By designing proper thickness filling factor of the superlattice barrier, ultrahigh magnetoresistance can be achieved. The tunnel magnetoresistance increases as the number of cells in the superlattice barrier increases. This ultrahigh magnetoresistance effect is attributed to the crystalline property of superlattices, similarly to the high magnetoresistance effect achieved by traditional crystalline MgO. There are more adjustable parameters, such as the lattice constant and the barrier height, in the artificial superlattice barrier than in a traditional crystalline-MgO barrier. This ultrahigh magnetoresistance effect may be used to design spintronic devices.