Units and Important Definitions

Units and Important Definitions

Appendix 1 Units and Important Definitions Fundamental physical constants Constant Avogadro constant Boltzmann constant elementary charge rest mass ...

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Appendix 1

Units and Important Definitions

Fundamental physical constants Constant Avogadro constant Boltzmann constant elementary charge rest mass of electron rest mass of proton absolute velocity permittivity of vacuum permeability of vacuum Planck constant reduced Planck constant Bohr magneton nuclear magneton fine structure constant electronic g-factor (Zeeman) —(spin-orbital) reduced Curie constant

Symbol

SI units

NK

6.022045 X lO^^moP^ 1.380662 X 10"^^ J K"^ 1.6021892 X 10"^^ C 9.109534 X 10"^^ kg 1.6726485 X 10"^^ kg 2.99792458 X 10^ ms"^ 8.854187818 x lO'^^C^N"^ m"^ 47rx lO-'^JA-^m"^ 6.626176 X lO-^'^Js 1.0545887 X 10"^^ J s 9.274078 X 10"^^ J T"^ 5.050824 X lO-^'^JT"^ 7.29735 X 10"^ 2.00231929 2.00463858 4.7141997 X lO-^Km^mol"'

kB,k e nig

nip

c £o Mo h

n = h/2n ptB = efi/2nig Atp = efi/2nip a — e^/(4ne()Pic) g g' Q = A^AMOMBA

Conversion factors {E/k), K temperature (E/k) wavenumber (E/hc)

(E/hc), cm 0.69503877

1.43876866

840

Appendices

Selected magnetic quantities Quantity

Relationship^

Unit

magnetic induction (physical vector)

B = IIQH

T = JA-^m-^

(volume)

M

Am"'

mass molar

Mp = M/p

magnetisation (physical vector)

Magnetic susceptibility (second-rank tensor)

volume, —differential

M^oi = M,Mp = Xab = Xab =

=

Am^kg-' Am^moP^

M,M/p

dimensionless

(dMJdHh)

fioi^MJdB,)

= (flo/V)Kab

—mean mass molar reduced

X = M/H =

fioM/B

m^kg-^ m^moP^

Xp = X/P Xmol = ^rXp = M,X/P Kab = -[^E/dBadBb)

Mr—^molar mass [kg mol ], p—density [kg m ], V—^volume

Spin-only values^ S

Curie constant. C (10-^ Km^ mol'-')

Product factor (Xmol r/Co), dimensionless

Effective magnetic moment,

1/2 1 3/2 2 5/2 3 7/2

4.71 12.6 23.6 37.7 55.0 75.4 99.0

1 8/3 5 8 35/3 16 21

1.73 2.83 3.87 4.90 5.91 6.93 7.94

Meff/MB

^ Curie constant: C = CQg^S{S-\-1)/3; product factor: P = C / Q ; effective magnetic moment: Meff/MB=2[S(5+1)]^/^

Sign conventions: (a) Condon-Shortley phase convention for spherical harmonics; ^ (b) constant factor in front of exchange coupUng constants: —J(S^ • 5^).