Magnetism

Question 1

This is a sensitive magnetometer which is based on superconducting loops containing Josephson junctions and is used to measure extremely subtle magnetic fields.

Answer 1

SQUID

superconducting quantum interference device​

Question 2

Gyromagnetic ratio for a transition metal with more than a half filled d-orbital shell

Answer 2

g>2

Question 3

Gyromagnetic ratio for a transition metal with less than a half filled d-orbital shell

Answer 3

g<2

Question 4

Gyromagnetic ratio for a free electron

Answer 4

2.0032

Question 5

μ_eff = g*(J*(J+1))^1/2

​

Answer 5

Magnetic moment for systems where Russell-Sauders does apply

Question 6

What are the possible values of S_tot for the system below if the two iron centers are magnetically couple?

Answer 6

S_tot ranges from 0 to 5

|5/2-5/2| —-> |5/2+5/2|

Question 7

What is the total spin of the system below if the two iron centers are antiferromagnetically coupled?

Answer 7

S_tot=0

5/2-5/2=0

Question 8

Are individual molecules that function as single-domain nanoscale magnetic particles below their blocking temperature.

Answer 8

Single-Molecule Magnets​

• large ground-state spin (S)
• negative magnetoanisotropy (negative zero-field splitting, D)

Question 9

A type of a magnetic exchange that may arise between ions in different oxidation states where two electrons are transferred simultaneously between the two metal centers and a bridge anion.

Answer 9

Double exchange​​

Simultaneous hop of an electron from Mn³⁺ to an O 2p and from the O 2p to an Mn⁴⁺ takes place​

Question 10

Is the antiferromagnetic coupling between two next-to-nearest neighbour cations through a non-magnetic anion.

Answer 10

Antiferromagnetic Superexchange​

The magnetic moment decreases and becomes less than even the normal paramagnetic substance​.

Question 11

The phenomenon in which the value of a physical property has a history dependence of physical system.

Answer 11

Hysteresis

Question 12

A measure of a material magnetization when a magnetic field is applied.

Answer 12

Susceptibility (χ)

Question 13

μ_eff = g*(S*(S+1))^1/2

For systems where Russell-Sauders does not apply​

Answer 13

The spin-only magnetic moment

Question 14

Antiparallel magnetic alignment of neighboring atoms electrons

Answer 14

Antiferromagnetic

Question 15

Residual magnetism resulting from both ferromagnetic and antiferromagnetic coupling. These alignments do not cancel out and there is a net magnetic moment.

Answer 15

Ferrimagnetic

Question 16

Parallel magnetic alignment of neighboring atoms.

This cooperative mechanim leads to states of highest spin multiplicity through electron alignment.

Answer 16

Ferromagnetic

Question 17

Unpaired electrons and magnetic moment is positive.

Answer 17

Paramagnetic

Question 18

No unpaired electrons. Magnetic moment is zero or slightly negative

Answer 18

Diamagnetic