Ferrimagnetism configuration of GaFeO3

 

hanabi - 2020-07-25

Hi,

I'm trying to calculate the Ferrimagnetism state of GaFeO3, so the first four iron atoms should have a different magnetude of spin moment to the rest of four iron atoms. My configuration is at below

tasks
 0

xctype
  20 0 0

emd_dim
  3

nwrite
  1

nints
  200

tempk
  20.0

ngridk
  5 5 4

spinpol
  .true.

spinorb
  .true.

cmagz
  .true.

epsengy
  0.5E-04

epspot
  0.2E-05

mixtype
  1

wplot
  800 200 3
  -0.4 0.2

sppath
'/path_to/elk_species/'

bfieldc
  0.0  0.0 -0.3

reducebf
  0.85

avec
   0.000000000       0.000000000       9.575676221
   16.47712561       0.000000000       0.000000000
   0.000000000       17.70367116       0.000000000

atoms
   3                                    : nspecies
'Ga.in'                                 : spfname
   8                                    : natoms; atposl, bfcmt below
    0.17810000    0.15000000    0.00000000    0.00000000  0.00000000  0.00000000
    0.32190000    0.65000000    0.50000000    0.00000000  0.00000000  0.00000000
    0.67810000    0.35000000    0.00000000    0.00000000  0.00000000  0.00000000
    0.82190000    0.85000000    0.50000000    0.00000000  0.00000000  0.00000000
    0.81060000    0.15930000    0.30730000    0.00000000  0.00000000  0.00000000
    0.68940000    0.65930000    0.80730000    0.00000000  0.00000000  0.00000000
    0.31060000    0.34070000    0.30730000    0.00000000  0.00000000  0.00000000
    0.18940000    0.84070000    0.80730000    0.00000000  0.00000000  0.00000000
'Fe.in'                                 : spfname
   8                                    : natoms; atposl, bfcmt below
    0.18860000    0.15380000    0.58310000    0.00000000  0.00000000  0.65
    0.31140000    0.65380000    0.08310000    0.00000000  0.00000000  0.65
    0.68860000    0.34620000    0.58310000    0.00000000  0.00000000  0.65
    0.81140000    0.84620000    0.08310000    0.00000000  0.00000000  0.65
    0.67950000    0.03460000    0.79980000    0.00000000  0.00000000  0.0
    0.82050000    0.53460000    0.29980000    0.00000000  0.00000000  0.0
    0.17950000    0.46540000    0.79980000    0.00000000  0.00000000  0.0
    0.32050000    0.96540000    0.29980000    0.00000000  0.00000000  0.0
'O.in'                                  : spfname
  24                                    : natoms; atposl, bfcmt below
    0.97160000    0.32280000    0.42620000    0.00000000  0.00000000  0.00000000
    0.52840000    0.82280000    0.92620000    0.00000000  0.00000000  0.00000000
    0.47160000    0.17720000    0.42620000    0.00000000  0.00000000  0.00000000
    0.02840000    0.67720000    0.92620000    0.00000000  0.00000000  0.00000000
    0.51420000    0.48640000    0.43110000    0.00000000  0.00000000  0.00000000
    0.98580000    0.98640000    0.93110000    0.00000000  0.00000000  0.00000000
    0.01420000    0.01360000    0.43110000    0.00000000  0.00000000  0.00000000
    0.48580000    0.51360000    0.93110000    0.00000000  0.00000000  0.00000000
    0.65410000    0.99790000    0.20220000    0.00000000  0.00000000  0.00000000
    0.84590000    0.49790000    0.70220000    0.00000000  0.00000000  0.00000000
    0.15410000    0.50210000    0.20220000    0.00000000  0.00000000  0.00000000
    0.34590000    0.00210000    0.70220000    0.00000000  0.00000000  0.00000000
    0.14800000    0.15930000    0.19740000    0.00000000  0.00000000  0.00000000
    0.35200000    0.65930000    0.69740000    0.00000000  0.00000000  0.00000000
    0.64800000    0.34070000    0.19740000    0.00000000  0.00000000  0.00000000
    0.85200000    0.84070000    0.69740000    0.00000000  0.00000000  0.00000000
    0.84370000    0.16950000    0.67170000    0.00000000  0.00000000  0.00000000
    0.65630000    0.66950000    0.17170000    0.00000000  0.00000000  0.00000000
    0.34370000    0.33050000    0.67170000    0.00000000  0.00000000  0.00000000
    0.15630000    0.83050000    0.17170000    0.00000000  0.00000000  0.00000000
    0.51660000    0.17360000    0.93830000    0.00000000  0.00000000  0.00000000
    0.98340000    0.67360000    0.43830000    0.00000000  0.00000000  0.00000000
    0.01660000    0.32640000    0.93830000    0.00000000  0.00000000  0.00000000
    0.48340000    0.82640000    0.43830000    0.00000000  0.00000000  0.00000000

But it always gives the antiferromagnetic value for iron's moment. For example,

  species :    2 (Fe)
   atom    1                 :   -3.724058938    
   atom    2                 :   -3.724058938    
   atom    3                 :   -3.725020912    
   atom    4                 :   -3.725020912    
   atom    5                 :    3.726328720    
   atom    6                 :    3.726328720    
   atom    7                 :    3.726236290    
   atom    8                 :    3.726236290 

I'm wondering how to set the config to get a ferrimagnetism result.

Thank you ,
Best regards.

 

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  Last edit: hanabi 2020-07-25

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  mfechner - 2020-07-27

  Dear Hanabi,

  Firstly, GaFeO3 is considered as a correlated insulator you want to try also DFT+U as an option, by the way. From your ouput I read that you are getting an AFM solution half spins up half down, with no net moment the reason being that elk finds this as the lowest groundstate for your starting configuration. If you are interested in something with a ferrimagnetic net moment I rather suggest you to put 5 spins up and 3 down in your input card which should result into something with a net moment.

   

• 
  

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  hanabi - 2020-07-27

  Hi Mfechner

  Thanks for your suggestion, I'd like to use DFT+U as well, but before that I'd prefer to get a ferrimagnetic net moment. I'll try the 5 spins up and 3 down to see what's happen.

  Best regards.

   

• • • 
      

mfechner - 2020-07-27

No problem are you using GGA currently? Could you check if this gives you an insulating state?

If yes, then the you always will have a net moment of about 4 muB per site, depending on the MT.
You also may consider switching off spin orbit for testing as this will not change to much here.

best
Michael

 https://sourceforge.net/p/elk/discussion/897820/thread/9bc199e32e/