{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T17:56:51Z","timestamp":1777571811896,"version":"3.51.4"},"reference-count":44,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2016,7,4]],"date-time":"2016-07-04T00:00:00Z","timestamp":1467590400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Fondaziona Cariplo","award":["2013-0735"],"award-info":[{"award-number":["2013-0735"]}]},{"name":"Regione Lombardia and Fondazione Cariplo","award":["2013-1760"],"award-info":[{"award-number":["2013-1760"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The fine control of the exchange coupling strength and blocking temperature ofexchange bias systems is an important requirement for the development of magnetoresistive sensors with two pinned electrodes. In this paper, we successfully tune these parameters in top- and bottom-pinned systems, comprising 5 nm thick Co40Fe40B20 and 6.5 nm thick Ir22Mn78 films. By inserting Ru impurities at different concentrations in the Ir22Mn78 layer, blocking temperatures ranging from 220 \u00b0C to 100 \u00b0C and exchange bias fields from 200 Oe to 60 Oe are obtained. This method is then applied to the fabrication of sensors based on magnetic tunneling junctions consisting of a pinned synthetic antiferromagnet reference layer and a top-pinned sensing layer. This work paves the way towards the development of new sensors with finely tuned magnetic anisotropies.<\/jats:p>","DOI":"10.3390\/s16071030","type":"journal-article","created":{"date-parts":[[2016,7,4]],"date-time":"2016-07-04T10:04:21Z","timestamp":1467626661000},"page":"1030","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["Exchange Bias Tuning for Magnetoresistive Sensors by Inclusion of Non-Magnetic Impurities"],"prefix":"10.3390","volume":"16","author":[{"given":"Parikshit","family":"Sharma","sequence":"first","affiliation":[{"name":"Dipartimento di Fisica, Politecnico di Milano, via Giuseppe Colombo, 81, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Edoardo","family":"Albisetti","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica, Politecnico di Milano, via Giuseppe Colombo, 81, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marco","family":"Monticelli","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica, Politecnico di Milano, via Giuseppe Colombo, 81, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Riccardo","family":"Bertacco","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica, Politecnico di Milano, via Giuseppe Colombo, 81, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9273-1884","authenticated-orcid":false,"given":"Daniela","family":"Petti","sequence":"additional","affiliation":[{"name":"Dipartimento di Fisica, Politecnico di Milano, via Giuseppe Colombo, 81, 20133 Milano, Italy"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2016,7,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"4447","DOI":"10.3390\/s120404447","article-title":"Gamma irradiation of magnetoresistive sensors for planetary exploration","volume":"12","author":"Sanz","year":"2012","journal-title":"Sensors"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"7919","DOI":"10.3390\/s91007919","article-title":"Magnetic Field Sensors Based on Giant Magnetoresistance (GMR) Technology: Applications in Electrical Current Sensing","volume":"9","author":"Reig","year":"2009","journal-title":"Sensors"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"28807","DOI":"10.3390\/s151128807","article-title":"Vehicle position estimation based on magnetic markers: Enhanced accuracy by compensation of time delays","volume":"15","author":"Byun","year":"2015","journal-title":"Sensors"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2","DOI":"10.1016\/S0924-4247(01)00621-5","article-title":"Magnetic sensors for automotive applications","volume":"91","author":"Treutler","year":"2001","journal-title":"Sens. Actuators A Phys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"455","DOI":"10.1016\/j.tibtech.2004.06.006","article-title":"Magnetoresistive-based biosensors and biochips","volume":"22","author":"Graham","year":"2004","journal-title":"Trends Biotechnol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"39","DOI":"10.1016\/j.snb.2014.04.055","article-title":"Photolithographic bio-patterning of magnetic sensors for biomolecular recognition","volume":"200","author":"Albisetti","year":"2014","journal-title":"Sens. Actuators B Chem."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2690","DOI":"10.1016\/j.bios.2009.01.040","article-title":"Femtomolar limit of detection with a magnetoresistive biochip","volume":"24","author":"Martins","year":"2009","journal-title":"Biosens. Bioelectron."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Shen, W., Schrag, B.D., Carter, M.J., and Xiao, G. (2008). Quantitative detection of DNA labeled with magnetic nanoparticles using arrays of MgO-based magnetic tunnel junction sensors. Appl. Phys. Lett., 93.","DOI":"10.1063\/1.2963970"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"314","DOI":"10.1038\/nnano.2011.45","article-title":"Quantification of protein interactions and solution transport using high-density GMR sensor arrays","volume":"6","author":"Gaster","year":"2011","journal-title":"Nat. Nanotechnol."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Albisetti, E., Petti, D., Damin, F., Cretich, M., Bagnati, M., Sola, L., Chiari, M., and Bertacco, R. (2013). Optimization of the bio-functionalized area of magnetic biosensors. Eur. Phys. J. B, 86.","DOI":"10.1140\/epjb\/e2013-30676-4"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1648","DOI":"10.1126\/science.1096841","article-title":"Femtotesla magnetic field measurement with magnetoresistive sensors","volume":"304","author":"Pannetier","year":"2004","journal-title":"Science"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3512","DOI":"10.1109\/TMAG.2013.2239274","article-title":"Integration of TMR sensors in silicon microneedles for magnetic measurements of neurons","volume":"49","author":"Amaral","year":"2013","journal-title":"IEEE Trans. Magn."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Amaral, J., Cardoso, S., Freitas, P.P., and Sebasti\u00e3o, A.M. (2011). Toward a system to measure action potential on mice brain slices with local magnetoresistive probes. J. Appl. Phys., 109.","DOI":"10.1063\/1.3562915"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Beach, R.S., McCord, J., Webb, P., and Mauri, D. (2002). Orthogonal pinning of two ferromagnetic layers in a synthetic spin valve. Appl. Phys. Lett., 80.","DOI":"10.1063\/1.1485106"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Wis\u0301niowski, P., Almeida, J.M., Cardoso, S., Barradas, N.P., and Freitas, P.P. (2008). Effect of free layer thickness and shape anisotropy on the transfer curves of MgO magnetic tunnel junctions. J. Appl. Phys., 103.","DOI":"10.1063\/1.2838626"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2014","DOI":"10.1063\/1.2839311","article-title":"MgO based picotesla field sensors","volume":"103","author":"Chaves","year":"2008","journal-title":"J. Appl. Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"30311","DOI":"10.3390\/s151229809","article-title":"Ultra-Compact 100 \u00d7 100 \u03bcm2 Footprint Hybrid Device with Spin-Valve Nanosensors","volume":"15","author":"Leitao","year":"2015","journal-title":"Sensors"},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Liu, X., Ren, C., and Xiao, G. (2002). Magnetic tunnel junction field sensors with hard-axis bias field. J. Appl. Phys., 92.","DOI":"10.1063\/1.1507818"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Zeng, Z.M., Khalili Amiri, P., Katine, J.A., Langer, J., Wang, K.L., and Jiang, H.W. (2012). Nanoscale magnetic tunnel junction sensors with perpendicular anisotropy sensing layer. Appl. Phys. Lett., 101.","DOI":"10.1063\/1.4744914"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Teixeira, J.M., Ventura, J., Ferna\u0301ndez-Garci\u0301a, M.P., Araujo, J.P., Sousa, J.B., Wisniowski, P., Leitao, D.C., and Freitas, P.P. (2012). Exchange biased CoFeB-MgO tunnel junctions at the onset of perpendicular anisotropy with in-plane\/out-of-plane sensing capabilities. J. Appl. Phys., 111.","DOI":"10.1063\/1.3693585"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2006","DOI":"10.1063\/1.2836721","article-title":"Field detection in single and double barrier MgO magnetic tunnel junction sensors","volume":"103","author":"Almeida","year":"2008","journal-title":"J. Appl. Phys."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Chen, J.Y., Feng, J.F., and Coey, J.M.D. (2012). Tunable linear magnetoresistance in MgO magnetic tunnel junction sensors using two pinned CoFeB electrodes. Appl. Phys. Lett., 100.","DOI":"10.1063\/1.3701277"},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Negulescu, B., Lacour, D., Montaigne, F., Gerken, A., Paul, J., Spetter, V., Marien, J., Duret, C., and Hehn, M. (2009). Wide range and tunable linear magnetic tunnel junction sensor using two exchange pinned electrodes. Appl. Phys. Lett., 95.","DOI":"10.1063\/1.3226676"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"3719","DOI":"10.1109\/TMAG.2012.2200468","article-title":"Large area and low aspect ratio linear magnetic tunnel junctions with a soft-pinned sensing layer","volume":"48","author":"Ferreira","year":"2012","journal-title":"IEEE Trans. Magn."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"203","DOI":"10.1016\/S0304-8853(98)00266-2","article-title":"Exchange bias","volume":"192","author":"Schuller","year":"1999","journal-title":"J. Magn. Magn. Mater."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"5519","DOI":"10.1063\/1.369880","article-title":"The dependence of the antiferromagnet\/ferromagnet blocking temperature on antiferromagnet thickness and deposition conditions","volume":"85","author":"Devasahayam","year":"1999","journal-title":"J. Appl. Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"883","DOI":"10.1016\/j.jmmm.2009.12.011","article-title":"A new paradigm for exchange bias in polycrystalline thin films","volume":"322","year":"2010","journal-title":"J. Magn. Magn. Mater."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"e91","DOI":"10.1016\/j.jmmm.2006.01.188","article-title":"Antiferromagnet IrMn thickness dependence in exchange-biased perpendicular magnetic anisotropy based on CoFe\/Pt\/CoFe\/[IrMn(tIrMn)] multilayers","volume":"304","author":"Lee","year":"2006","journal-title":"J. Magn. Magn. Mater."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Prejbeanu, I.L., Kerekes, M., Sousa, R.C., Sibuet, H., Redon, O., Dieny, B., and Nozi\u00e8res, J.P. (2007). Thermally assisted MRAM. J. Phys. Condens. Matter, 19.","DOI":"10.1088\/0953-8984\/19\/16\/165218"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1038\/nnano.2016.25","article-title":"Nanopatterning reconfigurable magnetic landscapes via thermally assisted scanning probe lithography","volume":"11","author":"Albisetti","year":"2016","journal-title":"Nat. Nanotechnol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"230","DOI":"10.1016\/j.jmmm.2015.07.009","article-title":"Domain wall engineering through exchange bias","volume":"400","author":"Albisetti","year":"2016","journal-title":"J. Magn. Magn. Mater."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2706","DOI":"10.1002\/adma.201000146","article-title":"On-chip manipulation of protein-coated magnetic beads via domain-wall conduits","volume":"22","author":"Donolato","year":"2010","journal-title":"Adv. Mater."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1688","DOI":"10.1126\/science.1108813","article-title":"Magnetic domain-wall logic","volume":"309","author":"Allwood","year":"2005","journal-title":"Science"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Yuasa, S., Suzuki, Y., Katayama, T., and Ando, K. (2005). Characterization of growth and crystallization processes in CoFeB\/MgO\/CoFeB magnetic tunnel junction structure by reflective high-energy electron diffraction. Appl. Phys. Lett., 87.","DOI":"10.1063\/1.2140612"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Malinowski, G., Hehn, M., Robert, S., Lenoble, O., and Schuhl, A. (2005). Correlation between structural quality and magnetic properties of IrMn-based multilayers. J. Appl. Phys., 98.","DOI":"10.1063\/1.2136233"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1016\/j.bios.2013.03.016","article-title":"Conditions for efficient on-chip magnetic bead detection via magnetoresistive sensors","volume":"47","author":"Albisetti","year":"2013","journal-title":"Biosens. Bioelectron."},{"key":"ref_37","first-page":"149","article-title":"Magnetic Tunneling Junctions for biosensors: Form the growth to the detection","volume":"35","author":"Petti","year":"2012","journal-title":"Nuovo Cim. C"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Donolato, M., Sogne, E., Dalslet, B.T., Cantoni, M., Petti, D., Cao, J., Cardoso, F., Cardoso, S., Freitas, P.P., and Hansen, M.F. (2011). On-chip measurement of the Brownian relaxation frequency of magnetic beads using magnetic tunneling junctions. Appl. Phys. Lett., 98.","DOI":"10.1063\/1.3554374"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1063\/1.3658854","article-title":"Positive exchange bias in as-deposited ion-beam sputtered IrMnCoFeB system","volume":"110","author":"Fulara","year":"2011","journal-title":"J. Appl. Phys."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Kerr, E., van Dijken, S., and Coey, J.M.D. (2005). Influence of the annealing field strength on exchange bias and magnetoresistance of spin valves with IrMn. J. Appl. Phys., 97.","DOI":"10.1063\/1.1895474"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"012501","DOI":"10.1063\/1.2956680","article-title":"Exchange bias of spin valve structure with a top-pinned Co40Fe40B20\/IrMn","volume":"93","author":"You","year":"2008","journal-title":"Appl. Phys. Lett."},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Fernandez-Outon, L.E., Arau\u0301jo Filho, M.S., Arau\u0301jo, R.E., Ardisson, J.D., and Macedo, W.A.A. (2013). Setting temperature effect in polycrystalline exchange-biased IrMn\/CoFe bilayers. J. Appl. Phys., 113.","DOI":"10.1063\/1.4795211"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Anderson, G., Huai, Y., and Miloslawsky, L. (2000). CoFe\/IrMn exchange biased top, bottom, and dual spin valves. J. Appl. Phys., 87.","DOI":"10.1063\/1.372907"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1109\/20.750623","article-title":"Spin valve and dual spin valve heads with synthetic antiferromagnets","volume":"35","author":"Zhu","year":"1999","journal-title":"IEEE Trans. Magn."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/7\/1030\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T19:25:23Z","timestamp":1760210723000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/16\/7\/1030"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2016,7,4]]},"references-count":44,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2016,7]]}},"alternative-id":["s16071030"],"URL":"https:\/\/doi.org\/10.3390\/s16071030","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2016,7,4]]}}}