04_08_86 - M AGNETIC SUSCEPTIBILITY OF THE ELEMENTS AND...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
MAGNETIC SUSCEPTIBILITY OF THE ELEMENTS AND INORGANIC COMPOUNDS When a material is placed in a magnetic field H , a magnetiza- tion (magnetic moment per unit volume) M is induced in the ma- terial which is related to H by M = κ H , where κ is called the volume susceptibility. Since H and M have the same dimensions, κ is di- mensionless. A more useful parameter is the molar susceptibility χ m , defined by χ κ κ ρ m m = = V M / where V m is the molar volume of the substance, M the molar mass, and ρ the mass density . When the cgs system is used, the custom- ary units for χ m are cm 3 mol –1 ; the corresponding SI units are m 3 mol –1 . Substances that have no unpaired electron orbital or spin an- gular momentum generally have negative values of χ m and are called diamagnetic. Their molar susceptibility varies only slightly with temperature. Substances with unpaired electrons, which are termed paramagnetic, have positive χ m and show a much stronger temperature dependence, varying roughly as 1/ T . The net sus- ceptibility of a paramagnetic substance is the sum of the paramag- netic and diamagnetic contributions, but the former almost always dominates. This table gives values of χ m for the elements and selected inor- ganic compounds. All values refer to nominal room temperature (285 to 300 K) unless otherwise indicated. When the physical state (s = solid, l = liquid, g = gas, aq = aqueous solution) is not given, the most common crystalline form is understood. An entry of Ferro. indicates a ferromagnetic substance. Substances are arranged in alphabetical order by the most com- mon name, except that compounds such as hydrides, oxides, and acids are grouped with the parent element (the same ordering used in the table “Physical Constants of Inorganic Compounds”). In keeping with customary practice, the molar susceptibility is given here in units appropriate to the cgs system. These values should be multiplied by 4π to obtain values for use in SI equations (where the magnetic field strength H has units of A m –1 ). References 1. Landolt-Börnstein, Numerical Data and Functional Relationships in Science and Technology, New Series, II/16 , Diamagnetic Susceptibility, Springer-Verlag, Heidelberg , 1986 . 2. Landolt-Börnstein, Numerical Data and Functional Relationships in Science and Technology, New Series , III/19, Subvolumes a to i2, Magnetic Properties of Metals , Springer-Verlag, Heidelberg, 1986- 1992. 3. Landolt-Börnstein, Numerical Data and Functional Relationships in Science and Technology, New Series , II/2, II/8, II/10, II/11,and II/12a, Coordination and Organometallic Transition Metal Compounds , Springer-Verlag, Heidelberg, 1966-1984. 4.
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 6

04_08_86 - M AGNETIC SUSCEPTIBILITY OF THE ELEMENTS AND...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online