Magnetic Hysteresis Loop (2D) — B-H Curve, Coercivity & Remanence

Material

Applied Field

H amplitude 1000 A/m

Sweep speed 1.0×

Coercivity H_c (custom material) 80 A/m

Live Readout

Applied H

0 A/m

Flux B

0.000 T

Saturation B_s

—

Remanence B_r

—

Coercivity H_c

—

Loop area (loss/cycle)

—

How it works

The applied field H(t) is a sine sweep. The instantaneous flux density B relaxes toward a saturation target that depends on which way H is currently moving — a simplified Jiles–Atherton-style anhysteretic model:

B_target(H) = Bs · tanh[(H − sign(dH/dt)·Hc) / Hsat]
dB per step ≤ (2·Bs/Hsat) · |dH| · 1.5   (rate-limited relaxation)

Because the target flips sign with the sweep direction, the rising branch (H increasing) and falling branch (H decreasing) trace two different curves — the ascending branch sits below H=0 by −Hc, the descending branch sits above by +Hc — which is exactly what opens up the hysteresis loop. Where they cross the vertical axis is the remanence B_r = Bs·tanh(Hc/Hsat); where the loop crosses the horizontal axis is the coercivity H_c itself.

Material presets — load real relative orderings of B_s, H_c and H_sat for soft iron, grain-oriented silicon steel, hard (spring) steel and sintered neodymium.
Custom — drag H_c directly and watch the loop widen or narrow in real time, independent of any preset.
Loop area — ∮H·dB (numerically integrated from the traced points), reported in J/m³ — the heat dissipated per cubic metre per magnetisation cycle.

Rising branch (H↑) Falling branch (H↓) Current (H, B)