Patent ID: 7485937

Claim:
A tunnel junction device, comprising: a first electrode; a second electrode; and an electrically insulating layer arranged between the first electrode and the second electrode; wherein: the first electrode comprises an A 1-x B x M 1-y M′ y O 3-δ oxide ferromagnetic (including ferrimagnetic) electroconductive solid material, wherein: x and y satisfy the conditions: 0≦x≦1 and 0≦y≦1; δ represents an oxygen deficiency; A represents an element selected from the group consisting of Ca, Sr, Ba, and other alkaline earth elements, La and other rare earth elements, and elements including Y, Bi, and Pb; B represents an element that is different from A, selected from the group consisting of Ca, Sr, Ba, and other alkaline earth elements, La and other rare earth elements, elements including Y, Bi, and Pb; M represents an element selected from the group consisting of Mn, Fe, Co, Ni, or Cu and other transition metal elements; and M′ represents an element selected from the group consisting of Mn, Mn, Fe, Co, Ni, or Cu and other transition metal elements M′ being different from “M”; and the second electrode comprises an A 1-x′ B x′ M 1-y′ M′ y′ O 3-δ oxide ferromagnetic (including ferrimagnetic) electroconductive solid material having a component ratio y′ that is not equal to y, wherein x′ and y′ satisfy the conditions: 0≦x′≦1, 0<y′≦1.