Thermal stability of exchange bias systems based on MnN

TY - JOUR

T1 - Thermal stability of exchange bias systems based on MnN

AU - Sinclair, John

AU - Hirohata, Atsufumi

AU - Vallejo Fernandez, Gonzalo

AU - Meinert, Markus

AU - O'Grady, Kevin Dermot

N1 - Funding Information: The authors would like to thank Dr. Stephen McVitie from the University of Glasgow for valuable help with TEM sample preparation. This work was part-funded through a project, HARFIR (Heusler Alloy Replacement For Iridium), by the European Commission under the 7th Framework Programme (FP7-NMP-2013-EU-Japan, Grant Agreement No. NMP3-SL-2013-604398). AH, GVF and KOG also acknowledge financial support from the UK EPSRC (EP/M02458X/1). © 2018 Elsevier B.V. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy.

PY - 2019/4/15

Y1 - 2019/4/15

N2 - At the present time there is a requirement to identify new antiferromagnetic alloys or compounds which might be suitable for the production of exchange bias systems. The phenomenon of exchange bias remains crucial for the operation of all read heads in hard disk drives and also has potential for use in magnetic random access memory (MRAM) systems. There is also an increasing interest in the use of antiferromagnets themselves in spintronic devices. Generally for applications the alloy IrMn is used, however given that Iridium is one of the rarest, and therefore most expensive elements on Earth, there is a search for alternative materials. In this paper we report on a study of the compound MnN in terms of its thermal stability. We have produced polycrystalline films of this compound with sub 10 nm grains and examined the thermal stability in layers of thicknesses of up to 30 nm. Using thermal activation studies we have determined a room temperature value of the anisotropy constant of this compound in a tetragonal structure of up to (6.3 ± 0.3) × 10 6 erg/cm 3 . The antiferromagnetic grains can be aligned by thermal annealing at an optimum temperature of 380 K. Above this temperature the magnetic properties deteriorate possibly due to nitrogen desorption.

AB - At the present time there is a requirement to identify new antiferromagnetic alloys or compounds which might be suitable for the production of exchange bias systems. The phenomenon of exchange bias remains crucial for the operation of all read heads in hard disk drives and also has potential for use in magnetic random access memory (MRAM) systems. There is also an increasing interest in the use of antiferromagnets themselves in spintronic devices. Generally for applications the alloy IrMn is used, however given that Iridium is one of the rarest, and therefore most expensive elements on Earth, there is a search for alternative materials. In this paper we report on a study of the compound MnN in terms of its thermal stability. We have produced polycrystalline films of this compound with sub 10 nm grains and examined the thermal stability in layers of thicknesses of up to 30 nm. Using thermal activation studies we have determined a room temperature value of the anisotropy constant of this compound in a tetragonal structure of up to (6.3 ± 0.3) × 10 6 erg/cm 3 . The antiferromagnetic grains can be aligned by thermal annealing at an optimum temperature of 380 K. Above this temperature the magnetic properties deteriorate possibly due to nitrogen desorption.

UR - http://www.scopus.com/inward/record.url?scp=85059463087&partnerID=8YFLogxK

U2 - 10.1016/j.jmmm.2018.12.018

DO - 10.1016/j.jmmm.2018.12.018

M3 - Article

VL - 476

SP - 278

EP - 283

JO - Journal of Magnetism and Magnetic Materials

JF - Journal of Magnetism and Magnetic Materials

SN - 0304-8853

ER -