Magnetic Aizu species

Simple list Vectors & bidirectors Property tensors Superspecies Point groups Explanations Authors
EXPLANATIONS & SYMBOLS

1. Species
Two different symmetry-breaking phase transitions in a crystalline material are said to belong to the same species G > F if their high-symmetry phase belong to same macroscopic symmetry class G, their low-symmetry phase belong to same macroscopic symmetry class F and for a suitably chosen domain state they have the same correspondence between the symmetry elements of symmetry groups G and F.

Species No.: serial number #... of a species from the list of all 212 species
G … crystallographic point group or class expressing the symmetry of the high-symmetry (parent, prototypic) phase
F … crystallographic point group of a representative domain state of the low-symmetry (descent, ferroic) phase or the associated oriented class.

When necessary, the orientation of the symmetry elements in F with respect to G is indicated by extra subscripts |,/,_,+. Their meaning is given in Section 3.


2. List of 122 magnetic point group classes
All the magnetic point groups are listed here.


3. Orientation of two-fold axes and mirror plane operations of F with respect to G
Symmetry of point group G Tetragonal and hexagonal Cubic
Orientation of two-fold axes 2 and mirror planes m of subgroup F
in rectangular coordinate system of point group G
[001] (001) <100> {100} <100> {100} <110> {110)
Notation 2| m| 2 m 2+ m+ 2\ m\


4. Internal symmetry of the tabulated macroscopic tensors
Symbol Matrix components Tensor Internal symmetry of a tensor Physical property
Symbol Number
c c 1 Scalar c Heat capacity
P Pi 3 Polar vector V Spontaneous polarization, pyroelectricity, electrocaloric effect
M Mi 3 Tensor of the 1st rank aεV Spontaneous magnetization, pyromagneticity, magnetocaloric effect
u
ε
uμ
εi,j
6 Tensor of the 2nd rank [V2] Strain*)
Permittivity
α αi,j 9 Tensor of the 2nd rank aεV2 Magnetoelectric effect
d
r
d
r
18 Tensor of the 3rd rank V[V2] Piezoelectricity*)
Electrooptics*)
Λ Λ 18 Tensor of the 3rd rank aεV[V2] Piezomagnecity*)
s sμν 21 Tensor of the 4th rank [[V2]2] Elastic compliance*)
Q
π
Qμ,ν
πμ,ν
36 Tensor of the 4th rank [V2]2 Electrostriction*)
Piezooptics*)

i, j = 1,2,3; μ,ν = 1,2,...,6.
*) in contracted (matrix) notation