Formulae

Question 1

fractional coverage?

Answer 1

= theta
= no. of occupied sites / total no. of surface sites

Question 2

what is theta in surface science?

Answer 2

fractional coverage

Question 3

using trigonometry to work out the spacing of steps?

Answer 3

tan (phi) = d/Ls

where d= layer spacing

Ls = length of going up one step

Question 4

what is the woods notation formula?

Answer 4

(b1/a1 x b2/a2)

(see examples)

M(100)c/p(b1/a1 x b2/a2) angle

Question 5

formula for electron binding energy?

Answer 5

electron binding energy = x-ray energy - kinetic energy of electrons

Question 6

formula for KE?

Answer 6

p^2 / 2me

Question 7

formula for momentum?

Answer 7

p = mv

Question 8

Formula for energy using voltage?

Answer 8

E = qV

Question 9

what is the value to convert J to eV and vice versa

Answer 9

eV = 1.602 x 10^19 J

Question 10

equation for de broglie wavelength?

Answer 10

Ydb = h/p = h/¬2meE

Question 11

what is pythagoras theorem?

Answer 11

a^2 +b^2 = c^2

Question 12

how to calculate the no. of diffraction spots

Answer 12

nmax = (¬2meE/h)d

(nmax + nmax)^2 = no. of diffraction spots

Question 13

What do you use for trigonometry?

Answer 13

SOHCAHTOA

Question 14

equation for the wavefunction describing the full surface barrier?

Answer 14

E∞ - Ef + E_surf-dip

Question 15

tunnelling probability?

Answer 15

tunnelling probability is proportional to |T|^2 ~ e^-2αL

where α depends on the barrier height, L is the barrier width (tip to surface distance)