Something like:
%06_Diffusion
clear
C0 = 0.2; % wt%
Cs = 1.0;
D = 2.6e-11;
x = 0:0.1:10; % mm
x = x./1000; % meter
indexer=1;
for factor=[10 20 40 100]
t = factor*3600;
Cxt(indexer,:) = C0 + (Cs - C0) *(1-erf(x./(2*sqrt(D*t))));
plot(x.*1000,Cxt(indexer,:),'-','Linewidth',2)
hold on
indexer=indexer+1;
end
title('\fontname{Arial}\fontsize{24} Time Dependent Carbon Profiles')
ylabel('\fontname{Arial}\fontsize{20} Concentration(%)')
xlabel('\fontname{Arial}\fontsize{20} Distance (mm)')
legend('10 hr', '20 hr', '40 hr', '100 hr','FontSize',18)
axis ([0 10 0 1.2])
grid on
ax1 = gca;
set(ax1,'XColor','k','YColor','k','Fontname','Arial','FontSize',18)
hold off
