MgGeN2

Contents

• Crystal Structures

• Synthesis and Growth Methods

• Electronic Band Structure

• Vibrational Properties

• Elastic Properties

• Dielectric Properties

• Second Order Non-Linearity

Crystal Structures

Space group: Pna2₁ (NOTE: For crystal modeling purposes, select the spacegroup as Pbn2₁ )

Point group: C_2v

Lattice constants:

Wyckoff positions:

Reference [4]

Synthesis and growth methods

Crystalline MgGeN₂ thin solid films growth: J.E. Van Nostrand at al; using the technique of molecular beam epitaxy (MBE) in a nitrogen plasma source.[3]

Electronic band structure

Band Gap:

Effective masses:

Conduction band minimum splittings and effective masses:

m_cx=0.31 m_cy=0.30 m_cz=0.28 [4]

Valence band maximum splittings and effective masses:

These data from reference [4]

Parameters of effective Hamiltonian: inverse-mass parameters A_i,B_i,C_i (.2h/2m_e), energy splitting (meV). [4]

Figures:

Figure 1: Electronic band structure of MgGeN₂ [4]

Figure 2: Band structure near valence band maximum [4]

Figure 3: Density of states and partial density of states [4]

Vibrational Properties

The phonons of the orthorhombic ternary nitrides at the gamma point can be classified by the irreducible representation of the point group C_2v.

There are 12 modes of each a₁, a₂, b₁, and b₂ symmetry.

All modes are Raman active. The a₁, b₁, b₂ are IR active as well. Longitudinal modes a_1L, b_1L, b_2L are affected by LO-TO splitting.

Computed frequencies of zone-center phonons: from reference [2]

Full set of zone-center phonon frequencies (in cm^-1): from reference [6]

Predicted Raman and IR spectra can be found in ref. [6] as well as phonon band structure and density of states.

Phonon calculations were also reported in [7] but do not provide a table of numerical results, only a figure.

Born effective charge tensor components:

Reference: [6]

Reference: [7]

Elastic Properties

Bulk moduli and pressure derivative:

Dielectric Properties