Magnetoresistive effect element and crystallization method of ferromagnetic layer
A magnetoresistive effect element includes a first ferromagnetic layer, a second ferromagnetic layer, a non-magnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer, and an additive-containing layer disposed at any position in a laminating direction, at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy containing at least one of boron and carbon, at least part of which is crystallized, and the additive-containing layer is a non-magnetic layer containing at least one of boron and carbon, and any one element selected from the group made of Ti, V, Cr, Cu, Zn, Zr, Mo, Ru, Pd, Ta, W, Ir, Pt and Au.
1 . A magnetoresistive effect element comprising: a first ferromagnetic layer, a second ferromagnetic layer, a non-magnetic layer disposed between the first ferromagnetic layer and the second ferromagnetic layer, an intermediate layer, and an additive-containing layer disposed at any position in a laminating direction,
wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer is a Heusler alloy containing at least one of boron and carbon, at least part of which is crystallized, and
the additive-containing layer is a non-magnetic layer containing both boron and carbon, and Ru.
2 . The magnetoresistive effect element according to claim 1 , wherein the additive-containing layer is two layers, and
the two additive-containing layers sandwich the first ferromagnetic layer and the second ferromagnetic layer.
3 . The magnetoresistive effect element according to claim 1 , wherein the additive-containing layer is in contact with at least one of the first ferromagnetic layer and the second ferromagnetic layer.
4 . The magnetoresistive effect element according to claim 1 , wherein, in the first ferromagnetic layer or the second ferromagnetic layer, a concentration of boron or carbon in a first surface close to the non-magnetic layer is lower than a concentration of boron or carbon in a second surface far from the non-magnetic layer.
5 . The magnetoresistive effect element according to claim 1 , wherein, in the first ferromagnetic layer or the second ferromagnetic layer, a concentration of boron or carbon is lower as it becomes closer to the non-magnetic layer.
6 . The magnetoresistive effect element according to claim 1 , wherein, in the Heusler alloy, a compound expressed by Co α Y β Z γ contains at least one of boron and carbon,
Y is a transition metal element or a precious metal element of the Co, Fe, Ni, Cu, Mn, V, Cr or Ti group, and Z is a typical element from group III to group V, and
α is 1 or 2 and β+γ>2 is satisfied.
7 . The magnetoresistive effect element according to claim 1 , wherein the Heusler alloy is a compound expressed by (Co 2 Fe β Z γ ) 1-δ B δ ,
Z is a typical element from group III to group V, and
β+γ≥2.3, β<γ, 0.5<β<1.9, 1.0<γ<2.0, and 0.1≤δ≤0.3 are satisfied.
8 . The magnetoresistive effect element according to claim 7 , wherein the compound satisfies 0.1≤δ≤0.25.
9 . The magnetoresistive effect element according to claim 1 , wherein the additive-containing layer is discontinuous in an in-plane direction crossing the laminating direction.
10 . The magnetoresistive effect element according to claim 1 , wherein the non-magnetic layer is a metal or an alloy containing any one element selected from the group consisting of Cu, Au, Ag, Cr and Al.
11 . The magnetoresistive effect element according to claim 1 , further comprising an intermediate layer,
wherein the intermediate layer is disposed at least one of between the first ferromagnetic layer and the non-magnetic layer and between the second ferromagnetic layer and the non-magnetic layer,
the intermediate layer is an alloy expressed by Ni or Ni ε Al 1-ε , and 0.5≤ε<1.0.
12 . The magnetoresistive effect element according to claim 11 , wherein a thickness of the intermediate layer is greater than 0 nm, and equal to or smaller than 0.63 nm.
13 . The magnetoresistive effect element according to claim 1 , further having a substrate,
wherein the substrate is a backing on which the first ferromagnetic layer, the second ferromagnetic layer, the non-magnetic layer and the additive-containing layer are laminated, and
the substrate is amorphous.
14 . The magnetoresistive effect element according to claim 1 , further comprising an intermediate layer,
wherein the intermediate layer is disposed at least one of between the first ferromagnetic layer and the non-magnetic layer and between the second ferromagnetic layer and the non-magnetic layer,
the intermediate layer is an alloy expressed by Ni ε Al 1-ε , and
0.5≤ε<1.0.