Hi,
I am wondering if anyone has any theories as to why I am observing an odd trend in my temperature profile during deposition. Below is the script. I have run this exact same script using a silver potential with no issue. The script works at low energies, but there is a massive temperature spike at the speed below that is not observed for silver. Could it be an issue with the potential? Seems odd to me as it works very well for the low energy simulations.
surface sputtering demo
------------------------ INITIALIZATION ----------------------------
dimension variables
box length in x and y
variable len index 15
height of layer
variable hgt index 10
delta between insert area and box
variable len0 index 0.1
full length minus delta
variable len1 equal {len}-{len0}
half length
variable len2 equal ${len}*0.5
#simulation set up
units real
atom_style full
boundary p p f
lattice fcc 4.07
region box block 0.0 {len} 0.0 {len} -1.0 20 units lattice
particle density in z-direction is inhomogeneous:
only do domain decomposition in x- and y-direction
processors * * 1
------------------------ regions and atom types ----------------------------
two atom types: surface and sputter atoms
create_box 2 box
region layer block 0.0 {len} 0.0 {len} 0.0 ${hgt}
create_atoms 2 region layer
mass 1 15.99
mass 2 196.967
region fixed block INF INF INF INF 0.0 0.1
group fixed region fixed
group mobile subtract all fixed
region simulation block 0.2 14.8 0.2 14.8 0.3 10
group simulation region simulation
group bath subtract all simulation fixed
reaxff force field
pair_style reax/c NULL checkqeq yes
pair_coeff * * AuCSOH.ff O Au
fix 1 all qeq/reax 1 0.0 10.0 1.0e-6 reax/c
neigh_modify delay 0
minimize 1.0e-5 1.0e-8 1000 10000
------------------------ equilibration----------------------------
reset_timestep 0
timestep 0.5
velocity mobile create 200 87287
use the temperature of the mobile layer atoms as reference
compute stemp simulation temp
compute pe all pe/atom
compute btemp bath temp
compute mtemp mobile temp
fix 2 mobile nve
fix 3 simulation langevin 200 200 50 982434
fix 4 bath langevin 200 200 50 982434
fix_modify 3 temp mtemp
thermo 100
thermo_style custom step atoms temp etotal c_btemp
thermo_modify temp mtemp
dump 1 all custom 100 md.dump id type x y z c_pe
minimal equilibration
run 1000
------------------------ insert ----------------------------
define region for inserting particles
region obox block 3.75 11.25 3.75 11.25 18 22 units lattice
region insert intersect 2 box obox
define group of inserted particles
group insert region insert
group insert type 1
deposit particles regularly into insert volume
fix 5 insert deposit 100 1 400 54321 region insert vz -.0469 -.0469
neigh_modify every 1 delay 0 check yes
group insert region insert
group insert type 1
time integrate inserted particles
fix 6 insert nve
remove thermostat on simulation atoms
unfix 3
#unfix 4
thermo_style custom step atomstemp pe etotal c_btemp c_stemp
thermo_modify temp mtemp
fix 7 all reax/c/species 10 10 100 species.out
handling of atoms the get bounced back from surface or sputtered off the surface
thermo_modify lost ignore
restart 1000 damage.*.restart
run 45000
The temp profile looks like: