16:00 〜 18:00
▲ [7p-PB7-14] Parasitic magnetization in doped Cr2O3 antiferromagnetic film
キーワード：Magnetoelectric effect, Antiferromagnet, Cr2O3
Magnetoelectric antiferromagnet Cr2O3 has received considerable attentions as a promising candidate for voltage controlled spintronic devices, since its antiferromagnetic spin reversal by applying both magnetic and electric fields have been demonstrated for Cr2O3 thin film systems [1,2]. Although Cr2O3 is an antiferromagnet, sometimes finite parasitic magnetization has been observed for Cr2O3 thin films; The origin of the parasitic magnetizations is still unclear, while it has attributed as the piezomagnetism [3], boundary magnetization [4], misfit dislocations [5], etc. We have observed positive exchange-bias phenomena in Cr2O3/Pt/Co thin film systems [6], which are also related to the parasitic magnetization in Cr2O3 films. Such a parasitic magnetization can utilize to reduce antiferromagnetic spin reversal energy in Cr2O3/Co exchange coupling system [7,8].
Recently we observed a larger parasitic magnetization in doped Cr2O3 film. In this study we investigated Al- and Ir- doping effect on the parasitic magnetization. With increasing both Al- and Ir-contents, the parasitic magnetization drastically increase; by about 3.7% Al-(Ir-) dope, volume magnetization of as large as 59 (4.9) emu/cc were obtained. Interestingly, the direction of the Cr2O3 volume magnetization against AFM domain is different between Al-doped and Ir-doped samples. In the case of Al-doped samples, the parasitic magnetization is parallel to the surface spin, while in the case of Ir-doped samples, it is anti-parallel to the surface spin. XRD results indicate both a and c value compression for Al-doped samples, and a and c value expansions for Ir-doped samples. Such a tuning of volume magnetization make Cr2O3 film more attractive.
This work was partly funded by JSPS KAKENHI Grant Number 16H05975 and ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Japan Government).
[1] T. Ashida et al., Appl. Phys. Lett., 104 (2014) 152409.
[2] T. Ashida et al., Appl. Phys. Lett., 106 (2015) 132407.
[3] S. Sahoo et al., Phil. Mag. Lett., 87 (2007) 259.
[4] P. Borisov et al., Phys. Rev. B, 993 (2016) 174415.
[5] T. Kosub et al., Nat. Commun., 8 (2017) 13985.
[6] T. Nozaki et al., Appl. Phys. Lett., 105 (2014) 212406.
[7] M. Al-Mahdawi et al., Phys. Rev. B, 95 (2017) 144423.
[8] T. Nozaki et al., Jpn. J. Appl. Phys., 56 (2017) 070302.
Recently we observed a larger parasitic magnetization in doped Cr2O3 film. In this study we investigated Al- and Ir- doping effect on the parasitic magnetization. With increasing both Al- and Ir-contents, the parasitic magnetization drastically increase; by about 3.7% Al-(Ir-) dope, volume magnetization of as large as 59 (4.9) emu/cc were obtained. Interestingly, the direction of the Cr2O3 volume magnetization against AFM domain is different between Al-doped and Ir-doped samples. In the case of Al-doped samples, the parasitic magnetization is parallel to the surface spin, while in the case of Ir-doped samples, it is anti-parallel to the surface spin. XRD results indicate both a and c value compression for Al-doped samples, and a and c value expansions for Ir-doped samples. Such a tuning of volume magnetization make Cr2O3 film more attractive.
This work was partly funded by JSPS KAKENHI Grant Number 16H05975 and ImPACT Program of Council for Science, Technology and Innovation (Cabinet Office, Japan Government).
[1] T. Ashida et al., Appl. Phys. Lett., 104 (2014) 152409.
[2] T. Ashida et al., Appl. Phys. Lett., 106 (2015) 132407.
[3] S. Sahoo et al., Phil. Mag. Lett., 87 (2007) 259.
[4] P. Borisov et al., Phys. Rev. B, 993 (2016) 174415.
[5] T. Kosub et al., Nat. Commun., 8 (2017) 13985.
[6] T. Nozaki et al., Appl. Phys. Lett., 105 (2014) 212406.
[7] M. Al-Mahdawi et al., Phys. Rev. B, 95 (2017) 144423.
[8] T. Nozaki et al., Jpn. J. Appl. Phys., 56 (2017) 070302.