A diffusion couple is formed when two different materials are allowed to interdiffuse at an elevated temperature (see Figure 5.8). For a block of pure metal A adjacent to a block of pure metal B, the concentration profile of A (in at % ) after interdiffusion is given by cx=50[1erf(2Dtx)] where x is measured from the original interface. For a diffusion couple with D=1014m2/s, plot the concentration profile of metal A over a range of 20m on either side of the original interface (x=0) after a time of 1 hour. [Note that erf(z)=erf(z).]