# US 11,309,115 B2 · Magnetoresistance effect element > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,309,115 B2 - Document ID: US11309115B2 - Status: Granted - Kind: B2 - Application number: 16/777,036 - Filed: 2020-01-30 - Published: 2020-08-06 - Granted: 2022-04-19 - Earliest claimed: 2019-02-05 - Assignees: TDK Corporation - Applicants: TDK Corporation - Inventors: Katsuyuki Nakada - Web page: https://patentgrep.com/patent/US11309115B2 ## CPC - H01F 10/193: Magnetic semiconductor compounds {(in general H01F1/40; multilayers, e.g. superlattices H01F10/3213)} - G01R 33/093: {using multilayer structures, e.g. giant magnetoresistance sensors (thin magnetic films H01F10/00)} - H01F 10/1936: {Half-metallic, e.g. epitaxial CrO2 or NiMnSb films} - H01F 10/324: {Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer} - H01F 10/325: {the spacer being noble metal} - H01F 10/3272: {by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets} - H01F 10/3268: {the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn} - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract A magnetoresistance effect element includes a first ferromagnetic layer, a second ferromagnetic layer, and a nonmagnetic spacer layer between the first ferromagnetic layer and the second ferromagnetic layer, in which at least one of the first ferromagnetic layer and the second ferromagnetic layer contains a metal compound having a half-Heusler type crystal structure, the metal compound contains a functional material, and X atoms, Y atoms, and Z atoms which form a unit lattice of the half-Heusler type crystal structure, and the functional material has an atomic number lower than an atomic number of any of the X atoms, the Y atoms, and the Z atoms. ## Claims ### Claim 1 A magnetoresistance effect element comprising: a first ferromagnetic layer; a second ferromagnetic layer; and a nonmagnetic spacer layer between the first ferromagnetic layer and the second ferromagnetic layer; wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer contains a metal compound having a half-Heusler type crystal structure, the metal compound contains a functional material, and X atoms, Y atoms, and Z atoms which form a unit lattice of the half-Heusler type crystal structure, and the functional material has an atomic number lower than an atomic number of any of the X atoms, the Y atoms, and the Z atoms, wherein the functional material is one or more of atoms selected from the group consisting of B and C, the metal compound has a crystal structure of an A2 structure, a C1b structure or a B2 structure. ### Claim 2 (depends on 1) The magnetoresistance effect element according to claim 1, wherein the functional material is boron, and a composition proportion of the functional material in the metal compound is 0.1 at % or more and 9.8 at % or less. ### Claim 3 (depends on 1) The magnetoresistance effect element according to claim 1, wherein the functional material is carbon, and a composition proportion of the functional material in the metal compound is 0.11 at % or more and 8.8 at % or less. ### Claim 4 (depends on 1) The magnetoresistance effect element according to claim 1, wherein the X atoms are one or more of atoms selected from the group consisting of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Cd, Ir, Pt, and Au, the Y atoms are one or more of atoms selected from the group consisting of Ti, V, Cr, Mn, Y, Zr, Nb, Hf, Ta, Gd, Tb, Dy, Hd, Er, Fe, Tm, Yb, and Lu, and the Z atoms are one or more of atoms selected from the group consisting of Al, Si, Ga, Ge, As, In, Sn, Sb, Tl, Pd, Bi, Se, and Te. ### Claim 5 (depends on 4) The magnetoresistance effect element according to claim 4, wherein the X atoms are one or more of atoms selected from the group consisting of Ni, Pd, Pt, Co, and Rh, the Y atoms are one or more of atoms selected from the group consisting of Mn, Cr, Fe, and V, and the Z atoms are one or more of atoms selected from the group consisting of Se, Te, and Sb. ### Claim 6 (depends on 1) The magnetoresistance effect element according to claim 1, wherein the metal compound has a crystal structure of a C1b structure or a B2 structure. ### Claim 7 (depends on 1) The magnetoresistance effect element according to claim 1, wherein one of the first ferromagnetic layer and the second ferromagnetic layer contains a metal compound having a half-Heusler type crystal structure, and the other thereof contains a metal compound having a full-Heusler type crystal structure, and the metal compound having a full-Heusler type crystal structure contains the X atoms, the Y atoms, and the Z atoms. ### Claim 8 (depends on 7) The magnetoresistance effect element according to claim 7, wherein the metal compound having a full-Heusler type crystal structure is expressed by a compositional formula Co2LαMβ, L atoms include at least one of Mn and Fe atoms, M atoms include at least one of Al, Si, Ge, and Ga atoms, α satisfies 0.7<α<1.6, and β satisfies 0.65<β<1.35. ### Claim 9 (depends on 1) The magnetoresistance effect element according to claim 1, comprising: an insertion layer between at least one of the first ferromagnetic layer and the second ferromagnetic layer, and the nonmagnetic spacer layer, wherein the insertion layer contains Co, Fe, or a CoFe alloy. ### Claim 10 (depends on 9) The magnetoresistance effect element according to claim 9, wherein a film thickness of the insertion layer is 0.2 nm or more and 1.2 nm or less. ### Claim 11 (depends on 1) The magnetoresistance effect element according to claim 1, wherein the nonmagnetic spacer layer is a metal. ### Claim 12 (depends on 11) The magnetoresistance effect element according to claim 11, wherein the nonmagnetic spacer layer is Ag or an Ag alloy. ### Claim 13 A magnetoresistance effect element comprising: a first ferromagnetic layer; a second ferromagnetic layer; and a nonmagnetic spacer layer between the first ferromagnetic layer and the second ferromagnetic layer; wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer contains a metal compound having a half-Heusler type crystal structure, the metal compound contains a functional material, and X atoms, Y atoms, and Z atoms which form a unit lattice of the half-Heusler type crystal structure; and the functional material has an atomic number lower than an atomic number of any of the X atoms, the Y atoms, and the Z atoms, wherein the functional material is nitrogen, and a composition proportion of the functional material in the metal compound is 0.09 at % or more and 7.2 at % or less, the metal compound has a crystal structure of an A2 structure, a C1b structure or a B2 structure, the functional material penetrates between lattices of the half-Heusler type crystal structure. ### Claim 14 A magnetoresistance effect element comprising: a first ferromagnetic layer; a second ferromagnetic layer; and a nonmagnetic spacer layer between the first ferromagnetic layer and the second ferromagnetic layer; wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer contains a metal compound having a half-Heusler type crystal structure, the metal compound contains a functional material, and X atoms, Y atoms, and Z atoms which form a unit lattice of the half-Heusler type crystal structure; and the functional material has an atomic number lower than an atomic number of any of the X atoms, the Y atoms, and the Z atoms, wherein the functional material is fluorine, and a composition proportion of the functional material in the metal compound is 0.13 at % or more and 7.2 at % or less. ### Claim 15 A magnetoresistance effect element comprising: a first ferromagnetic layer; a second ferromagnetic layer; and a nonmagnetic spacer layer between the first ferromagnetic layer and the second ferromagnetic layer; wherein at least one of the first ferromagnetic layer and the second ferromagnetic layer contains a metal compound having a half-Heusler type crystal structure, the metal compound contains a functional material, and X atoms, Y atoms, and Z atoms which form a unit lattice of the half-Heusler type crystal structure; and the functional material has an atomic number lower than an atomic number of any of the X atoms, the Y atoms, and the Z atoms, wherein the functional material is one or more of atoms selected from the group consisting of Li, Be, O, Na and Mg.