What is the minumum acceleration potential (V) that must be applied to a beam of free electrons for diffraction to occur in a crystal of niobium (Nb)? Express your answer in volts.

if BCC first plane to give maximum wavelenth is (110) plane.

Then use lambda = 2dsin(theta) but since you want to maximize the lamdba assume that (theta) = 90 degrees

So lambda = 2d only

d = a(lattice constant) / sqrt (h^2 + k+2 + l^2)

solve for a, plug in (110) for (hkl)

then use lambda = hc/eV

to solve for Volts

Answer 7

Peter answered
10 years ago

What is the minumum acceleration potential (V) that must be applied to a beam of free electrons for diffraction to occur in a crystal of niobium (Nb)? Express your answer in volts.

Any ideas?

2.6 *10^3 Volts

2.7*10^3, sorry

Dude its wrong again

Nb is BCC and if you solve it, it gives you 2667 Volts but when you put it as your answer it gives X mark :(

My solution

Has anyone the right answer?