How to generate random numbers in a data.frame with range

I have a data.list which I want to generate random numbers each list by a sequence.

I used sample function to create random numbers but even I created random numbers for list [[1]], for set [[2]] same numbers produced again. So, here how can I create different random numbers for the set [[2]].

here is the simple code;

data.list <- lapply(1:2, function(x) {
nrep <- 1
time <- rep(seq(90,54000,by=90),times=nrep) 
Mx <- rep(sort(sample(seq(0.012,-0.014,length.out = 600),replace=TRUE)), times=nrep)
My <- rep(sort(sample(seq(0.02,-0.02,length.out = 600),replace=TRUE)), times=nrep)
Mz <- rep(sort(sample(seq(-1,1,length.out=600),replace=TRUE)), times=nrep)
data.frame(time,Mx,My,Mz,set_nbr=x)
})