Interfacial thermal conductance of graphene-polymer nanocomposite

Hi all,

I use thermal/conductivity to calculate the interfacial thermal conductivity in graphene-polymer nanocomposites at T=300 K. However, the temperature profile of my result varies greatly (Tmin=100, Tmax=500). Can anybody help me to solve this problem. The following is my input file.

Calculation of Interfacial Thermal Conductivity

########## Initialization ###########################################################################

units real
dimension 3
boundary p p p
atom_style molecular

########## PCFF potential information (Class 2 Force-field) #########################################

neighbor 5.0 bin
neigh_modify every 1 delay 1
bond_style class2 # Define bond style
angle_style class2 # Define angle style
dihedral_style class2 # Define dihedral style
improper_style class2 # Define improper style
pair_style lj/class2 10.0

read_data data.Model_1 # Import geometrical data

########## Geometrical information ###################################################################

group polymer type 2 4 # Define polymer group
group graphene type 1 # Define graphene group

########## Output thermodynamics parameters ##########################################################

thermo_style custom step temp etotal vol ke
thermo 1000
thermo_modify lost warn

velocity polymer create 300 5812775 dist gaussian units box
velocity graphene create 300 5812778 dist gaussian units box

########## Calculate Temperature Profile #############################################################

compute ke all ke/atom

variable temp atom c_ke/(1.51.00.0019872041)

fix temp_polymer_profile polymer ave/spatial 10 10000 100000 z lower 0.05 v_temp file temp_polymer_1.profile units reduced
fix temp_graphene_profile graphene ave/spatial 10 10000 100000 z lower 0.5 v_temp file temp_graphene_1.profile units reduced

########## NVT Equilibration ##########################################################################

fix temp all temp/berendsen 300 300 5
fix nve all nve

timestep 0.25

run 500000

unfix temp

########## NEMD Calculation ###########################################################################

fix heat_swap all thermal/conductivity 200 z 20

fix e_exchange all ave/time 200 500 100000 f_heat_swap file e_exchange_1.dat

run 5000000

Kind regards,

M.C.