implement loss of remanence due to warming through Verwey transition in MPMS_analysis.ipynb

[Swanson-Hysell]

Jackson and Moskowitz (2020) describe that: The IRMDB software allows interactive analysis and calculation of TV, as well as the loss of remanence due to warming through the transition, using the derivative method of Liu et al. (2004). This loss of remanence calculation should be implemented in MPMS_analysis.ipynb.

[Swanson-Hysell]

Hey @peat22, can you have a look at how this is implemented in the Delphi/Pascal in Quantum Ferret? I am thinking that it makes sense to use the "magnetite curve" determined from the background fit. It seems one could either use the start and end of the magnetite curve (i.e. the first and last blue point blue). Or alternatively could take the excluded temperature range start and end as the before and after remanence values (either approach should give about the same answer if the background is decently fit).

[peat22]

I'll take a look at this tomorrow. Had a fun day struggling to get anaconda installed and working (Thanks Plinio!). And I thought Delphi was difficult to install!

…

On Mon, Feb 12, 2024, 12:37 Nick Swanson-Hysell ***@***.***> wrote: Hey @peat22 <https://github.com/peat22>, can you have a look at how this is implemented in the Delphi/Pascal in Quantum Ferret? I am thinking that it makes sense to use the "magnetite curve" determined from the background fit. It seems one could either use the start and end of the magnetite curve (i.e. the first and last blue point blue). Or alternatively could take the excluded temperature range start and end as the before and after remanence values (either approach should give about the same answer if the background is decently fit). Screenshot.2024-02-12.at.10.35.31.AM.png (view on web) <https://github.com/PmagPy/RockmagPy-notebooks/assets/4332322/b390ee56-4e67-4a06-900f-aa09cabc80f4> — Reply to this email directly, view it on GitHub <#2 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AGBXN3UFE3VILULW7LDY3KTYTJOQHAVCNFSM6AAAAABCTLPKPOVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTSMZZGMYTOMBUGI> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[Swanson-Hysell]

I have added initial functionality to do this calculation to the function verwey_estimate() with this code in commit 69ac714

remanence_loss = mgt_curve.iloc[0] - mgt_curve.iloc[-1]

and the notebook is updated as well to ingest these values and tabulate them 3ae66a1. The next step is to compare to values that are determined within the IRM Quantum Ferret software and to figure out what the relative value is within that software as well.

[Swanson-Hysell]

This first and last magnetite point approach gives slightly different values. Here are the current values calculated in the notebook:

specimen	verwey_temp	remanence_loss	t_range_background_min	t_range_background_max	excluded_t_min	excluded_t_max	poly_deg
NED18-2c	105.861068	0.003426	60	250	75	150	3
NED2-8c	116.140403	0.001674	50	260	75	150	3
NED4-1c	117.902959	0.000448	60	260	75	150	3

Here are the values that come out of TVviewer:

specimen	verwey_temp	remanence_loss	t_range_background_min	t_range_background_max	excluded_t_min	excluded_t_max	poly_deg
NED18-2c	105.9	0.00318	60	250	75	150	3
NED2-8c	116.2	0.00138	50	260	75	150	3
NED4-1c	117.9	0.000440	60	260	75	150	3

The Verwey temperature estimates look to be right on, while the delta FC [Am2/kg] are slightly different.

[Swanson-Hysell]

Rather than

remanence_loss = mgt_curve.iloc[0] - mgt_curve.iloc[-1]

It makes sense to integrate the magnetite derivative curve which can be implemented with:

remanence_loss = np.trapz(mgt_dM_dT, temps_dM_dT_background)

[Swanson-Hysell]

The resulting values for the example ECMB data are below and are closer to the values out of TVviewer:

specimen	verwey_temp	remanence_loss	t_range_background_min	t_range_background_max	excluded_t_min	excluded_t_max	poly_deg
NED18-2c	105.861068	0.003278	60	250	75	150	3
NED2-8c	116.145701	0.001548	60	260	75	150	3
NED4-1c	117.902959	0.000437	60	260	75	150	3