SOT MRAM time dependent simulation

[喬冠豪]

Hi Serban,

I've been simulating the magnetization time-dependent behaviour of a Pt(50nm x 50nm x 10nm)/CoFeB(radius 20nm, thickness 1nm) bilayer. However, when I applied a current density of above 10TA/m^2, I still can't drag the <Mz> down to nearly zero by spin Hall effect.

I used LLG-SA and enabled transport, sdemag, Oersted, strayfield, aniuni, exchange, Zeeman modules. Is this setting correct for simulating Pt/CoFeB under spin Hall effect? 

I attached the result under a 0.1ns current pulse (around 11TA/m^2)

Thanks a lot for the help

Kuan-Hao

[喬冠豪]

Here is my settings of the Pt(50nm x 50nm x 10nm)/CoFeB(radius 20nm, thickness 1nm) bilayer.

https://drive.google.com/drive/folders/1IiC8N_OHtPLxlqy_6MVJcYgcLdeR4wap?usp=sharing

I used the parameters given in the Online Materials Database and turned on pump_eff, ts_eff, tsi_eff.

I'm wondering whether the LLG-SA ode is capable of dealing with devices of the order of a nanometre or there is something important that I missed in my settings?

Thank you so much!

Best wishes,

Kuan-Hao

[Serban Lepadatu]

Hi Kuan-Hao,

I had a look and I think the problem is setup correctly. There's a large in-plane torque generated, however you may need to double check the K1 value (anisotropy constant) is not too large for your problem. The database defines it as 760 kJ/m^3, and there's a reference for it, but the out of plane anisotropy could be too large for your particular problem. Other than this, you may need to run the simulation for longer. For a quick test you could run this problem without the spin transport solver (transport module on, but just the LLG equation set), and instead generate SOT by enabling the SOTfield module (see manual for relevant parameters).

Other notes, you don't need the strayfield module (this is used to calculate stray field from fixed dipole meshes, but none are defined). You also don't need the sdemag module, just use the demag module in the CoFeB mesh (sdemag is used if there are multiple magnetic meshes).

Regards,
Serban

--
You received this message because you are subscribed to the Google Groups "Boris Computational Spintronics" group.
To unsubscribe from this group and stop receiving emails from it, send an email to boris-computational-s...@googlegroups.com.
To view this discussion on the web, visit

https://groups.google.com/d/msgid/boris-computational-spintronics/6371dcb3-bdc1-4a96-ba5d-4d4deef9778dn%40googlegroups.com

.

[喬冠豪]

Hi Serban，

Thank you so much for pointing out my problem.

I'll test for more details and check it.

Thank you so much!

Best wishes,

Kuan-Hao

Serban Lepadatu 在 2022年7月19日 星期二晚上8:55:47 [UTC+8] 的信中寫道：