How to simulate a wall constructed by metal atoms with temperature and oscillation

Dear lammps-user

I want to build a metal wall with the uppermost atom of wall having a constant temperature while the entire wall vibrates in a certain way. Using fix move command can make the wall vibrate, but after the temperature of the uppermost atom is controlled by fix nvt command, the wall atoms will spread irregularly. How does the wall vibrate while the atomic layer has a constant temperature? Thank you for your help.

You can use fix spring/self command to construct the spring wall and then you can apply fix nvt command to thermostat your walls.