Hello,
I've been trying to simulate multilayered systems and therefore I am setting the geometry and setting regions to different layers and I can only do that by putting multiple cells in the Z direction. The system I am using is the following
CellSize:=5.e-9
NumCells:=512
ZNumCells:= 6
SetGridSize(NumCells, NumCells, ZNumCells)
SetCellSize(CellSize, CellSize, 6.e-9)
SETPBC(6,6,0)
//Material
Msat=1000e3
Aex=1e-11
alpha = 0.007
anisC1=vector(1,1,0)
anisC2=vector(-1,1,0)
Kc1=5000
Kc2=0
In this system the demag kernel is:
B_demag = (-5.375485731444011e-05, 7.689423121822377e-05, -0.06891722977161407)
For this material and since its a thin film (36nm), I expect to have a demag in plane and I have an easy axis in the x-direction.
However, the demag values are not correct for an extended thin film (it is mostly out of plane...)
If I use only one cell in the Z direction of 36 nm:
CellSize:=5.e-9
NumCells:=512
ZNumCells:= 1
SetGridSize(NumCells, NumCells, ZNumCells)
SetCellSize(CellSize, CellSize, 36.e-9)
SETPBC(6,6,0)
setgeom(universe())
The B_demag = (0.0011605947511270642, 2.4958247274442513e-11, 1.287635509328311e-08)
I would have expected both to be the same, since its exactly the same system just one has 1 cell of 36nm, while the other system is 6 cells of 6nm each. I see that using only 2 cells also works, but for 3+ it fails and gives an out of plane component.
The rest of the code is completely equal in each case:
m =uniform(1,0,0)
relax()
FixDt = 1e-11;
// SOME FMR CODE HERE
Is this a problem on the mumax3 kernel calculation? I have seen other problems with it when changing the initial state of m.
Also, the simulations I want to do is to see the dipolar coupling between layers or different materials and therefore if the demag is not correct I wont get good results. :(
Thank you for any response or fix.
Marc
Hello,
I've been trying to simulate multilayered systems and therefore I am setting the geometry and setting regions to different layers and I can only do that by putting multiple cells in the Z direction. The system I am using is the following
CellSize:=5.e-9
NumCells:=512
ZNumCells:= 6
SetGridSize(NumCells, NumCells, ZNumCells)
SetCellSize(CellSize, CellSize, 6.e-9)
SETPBC(6,6,0)
//Material
Msat=1000e3
Aex=1e-11
alpha = 0.007
anisC1=vector(1,1,0)
anisC2=vector(-1,1,0)
Kc1=5000
Kc2=0
In this system the demag kernel is:
B_demag = (-5.375485731444011e-05, 7.689423121822377e-05, -0.06891722977161407)
For this material and since its a thin film (36nm), I expect to have a demag in plane and I have an easy axis in the x-direction.
However, the demag values are not correct for an extended thin film (it is mostly out of plane...)
If I use only one cell in the Z direction of 36 nm:
CellSize:=5.e-9
NumCells:=512
ZNumCells:= 1
SetGridSize(NumCells, NumCells, ZNumCells)
SetCellSize(CellSize, CellSize, 36.e-9)
SETPBC(6,6,0)
setgeom(universe())
The B_demag = (0.0011605947511270642, 2.4958247274442513e-11, 1.287635509328311e-08)
I would have expected both to be the same, since its exactly the same system just one has 1 cell of 36nm, while the other system is 6 cells of 6nm each. I see that using only 2 cells also works, but for 3+ it fails and gives an out of plane component.
The rest of the code is completely equal in each case:
m =uniform(1,0,0)
relax()
FixDt = 1e-11;
// SOME FMR CODE HERE
Is this a problem on the mumax3 kernel calculation? I have seen other problems with it when changing the initial state of m.
Also, the simulations I want to do is to see the dipolar coupling between layers or different materials and therefore if the demag is not correct I wont get good results. :(
Thank you for any response or fix.
Marc