Struct PhaseTransition 

pub struct PhaseTransition {
    pub a0: f64,
    pub tc: f64,
    pub b: f64,
    pub c: f64,
    pub temperature: f64,
}

Landau theory description of a second-order phase transition.

Free energy density: f(φ) = a(T) φ²/2 + b φ⁴/4 + c φ⁶/6 where a(T) = a₀ (T - T_c).

Fields

a0: f64

Coefficient a₀ (> 0).

tc: f64

Critical temperature T_c.

b: f64

Coefficient b of the φ⁴ term (> 0 for a normal second-order transition).

c: f64

Coefficient c of the φ⁶ term (stabilising; ≥ 0).

temperature: f64

Current temperature.

Implementations

impl PhaseTransition

pub fn new(a0: f64, tc: f64, b: f64, c: f64, temperature: f64) -> Self

Creates a new Landau free energy model.

pub fn a_coeff(&self) -> f64

Returns a(T) = a₀(T - T_c).

pub fn order_parameter(&self) -> f64

Returns the equilibrium order parameter φ* that minimises f(φ).

For T > T_c: φ* = 0. For T < T_c: φ* = √(-a(T)/b) (when c = 0 and b > 0).

pub fn free_energy_density(&self, phi: f64) -> f64

Returns the Landau free energy density at order parameter phi.

pub fn reduced_temperature(&self) -> f64

Returns the reduced temperature t = (T - T_c) / T_c.

pub fn mean_field_beta_exponent(&self) -> f64

Returns the critical exponent β (mean-field value = 1/2).

pub fn susceptibility(&self) -> f64

Returns the susceptibility χ ~ |T - T_c|^(-γ); mean-field γ = 1.

Trait Implementations

impl Clone for PhaseTransition

fn clone(&self) -> PhaseTransition

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for PhaseTransition

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.