A method of manufacturing a magnetoresistive stack comprising: depositing a seed region on an electrically conductive material of an electrode or a via, wherein depositing the seed region includes: depositing an alloy including nickel and chromium having a thickness greater than or equal to 40 Angstroms and a material composition of chromium in the range of 25-60% by atomic percent on and in direct contact with the electrically conductive material; depositing a fixed magnetic region on and in direct contact with the seed region, wherein depositing the fixed magnetic region includes: depositing a multilayer unpinned, fixed synthetic antiferromagnetic structure including (i) depositing a first ferromagnetic structure on and in direct contact with the seed region, (ii) depositing a coupling material on and in direct contact with the first ferromagnetic structure, and (iii) depositing a second ferromagnetic structure on and in direct contact with the coupling material; wherein depositing the first ferromagnetic structure of the multilayer unpinned, fixed synthetic antiferromagnetic structure of the fixed magnetic region on and in direct contact with the seed region includes depositing alternating layers of nickel and cobalt, including a layer of nickel on and in direct contact with the seed region; depositing a transition layer on and in direct contact with the second ferromagnetic structure, wherein the transition layer includes a non-ferromagnetic transition metal, and forming a reference layer over the transition layer, the reference layer comprising a high-iron alloy interface region, wherein the high-iron alloy interface region has at least 50% iron by atomic composition; depositing one or more dielectric layers wherein, after annealing, the one or more dielectric layers are on and in direct contact with the high-iron alloy interface region of the fixed magnetic region; and depositing a free magnetic region over the one or more dielectric layers. depositing an alloy including nickel and chromium having a thickness greater than or equal to 40 Angstroms and a material composition of chromium in the range of 25-60% by atomic percent on and in direct contact with the electrically conductive material; depositing a fixed magnetic region on and in direct contact with the seed region, wherein depositing the fixed magnetic region includes: depositing a multilayer unpinned, fixed synthetic antiferromagnetic structure including (i) depositing a first ferromagnetic structure on and in direct contact with the seed region, (ii) depositing a coupling material on and in direct contact with the first ferromagnetic structure, and (iii) depositing a second ferromagnetic structure on and in direct contact with the coupling material; wherein depositing the first ferromagnetic structure of the multilayer unpinned, fixed synthetic antiferromagnetic structure of the fixed magnetic region on and in direct contact with the seed region includes depositing alternating layers of nickel and cobalt, including a layer of nickel on and in direct contact with the seed region; depositing a transition layer on and in direct contact with the second ferromagnetic structure, wherein the transition layer includes a non-ferromagnetic transition metal, and forming a reference layer over the transition layer, the reference layer comprising a high-iron alloy interface region, wherein the high-iron alloy interface region has at least 50% iron by atomic composition; depositing one or more dielectric layers wherein, after annealing, the one or more dielectric layers are on and in direct contact with the high-iron alloy interface region of the fixed magnetic region; and depositing a free magnetic region over the one or more dielectric layers. depositing a multilayer unpinned, fixed synthetic antiferromagnetic structure including (i) depositing a first ferromagnetic structure on and in direct contact with the seed region, (ii) depositing a coupling material on and in direct contact with the first ferromagnetic structure, and (iii) depositing a second ferromagnetic structure on and in direct contact with the coupling material; wherein depositing the first ferromagnetic structure of the multilayer unpinned, fixed synthetic antiferromagnetic structure of the fixed magnetic region on and in direct contact with the seed region includes depositing alternating layers of nickel and cobalt, including a layer of nickel on and in direct contact with the seed region; depositing a transition layer on and in direct contact with the second ferromagnetic structure, wherein the transition layer includes a non-ferromagnetic transition metal, and forming a reference layer over the transition layer, the reference layer comprising a high-iron alloy interface region, wherein the high-iron alloy interface region has at least 50% iron by atomic composition; depositing one or more dielectric layers wherein, after annealing, the one or more dielectric layers are on and in direct contact with the high-iron alloy interface region of the fixed magnetic region; and depositing a free magnetic region over the one or more dielectric layers.