Changing magnetic flux → Electrical work

Matrix context

D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.

D.07 × C.09 · Changing magnetic flux × Caloric (magneto/electro/elasto)family: Caloric (magneto/electro/elasto)D.07 × C.04 · Changing magnetic flux × Pyroelectricfamily: Pyroelectric

Typed bounds on this route

Every limit the atlas holds for this route, as constraint records: reached through bounded_by claims on the route's own entities. Hard bounds (an upper bound or a formula) decide the thermodynamic-bound check above; benchmarks, constitutive relations and resource limits are listed and never decisive. No prose limit exists anywhere (pass 42).

• Carnot limit · formula-bound · hard, applies to this route
  η ≤ 1 − T_c/T_h for any heat engine between reservoirs at T_h and T_c

Steps

1. 01
   Changing magnetic flux —drives→ Magnetocaloric effectestablishedclaim record

   magnetic → thermal

   • adiabatic magnetisation or demagnetisation of a material near its ordering temperature

   solid · ferromagnet required · magnetic field required

   refs [1] [2] [3]
2. 02
   Magnetocaloric effect —produces→ Temporal temperature changeestablishedclaim record

   thermal → thermal

   refs [1] [2]
3. 03
   Temporal temperature change —drives→ Pyroelectric effectestablishedclaim record

   thermal → electrical · loss to thermal

   ΔP = p · ΔT · pyroelectric coefficient p [C/(m^2 K)]

   ΔT is the material's temperature change between two times, not a spatial temperature difference.

   • the temperature of the polar material must change in time (dT/dt ≠ 0); a static spatial temperature gradient alone produces no pyroelectric current
   • the material must be below its Curie temperature

   solid · ferroelectric required · transient only

   Re-spelled in loop-3 pass 30 from the temperature-gradient row, where it had sat as an indexing compromise, onto the temporal temperature change that is its physical driver.

   refs [4] [5] [6]
4. 04
   Pyroelectric effect —produces→ Separated surface chargeestablishedclaim record

   electrical → electrical

   refs [4]
5. 05
   Separated surface charge —converts into→ Electrical workestablishedclaim record

   electrical → electrical · loss to thermal

   • electrodes on the charged surfaces connected through a load

   refs [7]

Evidence for the complete composition · 0

No source on record for this exact composition. The sources below support the individual steps, not the route as a whole.

Evidence for the constituent relations · 7

1. [1]
   V. K. Pecharsky, K. A. Gschneidner Jr.. Giant magnetocaloric effect in Gd5(Si2Ge2) (1997)

   Physical Review Letters 78, 4494 · doi:10.1103/PhysRevLett.78.4494 · crossref ✓ 2026-09-19 · record
2. [2]
   K. A. Gschneidner Jr, V. K. Pecharsky, A. O. Tsokol. Recent developments in magnetocaloric materials (2005)

   Reports on Progress in Physics 68, 1479–1539 · doi:10.1088/0034-4885/68/6/R04 · crossref ✓ 2026-09-19 · record
3. [3]
   X. Moya, S. Kar-Narayan, N. D. Mathur. Caloric materials near ferroic phase transitions (2014)

   Nature Materials 13, 439–450 · doi:10.1038/nmat3951 · crossref ✓ 2026-09-19 · record
4. [4]
   S. B. Lang. Pyroelectricity: from ancient curiosity to modern imaging tool (2005)

   Physics Today 58(8), 31–36 · doi:10.1063/1.2062916 · crossref ✓ 2026-09-19 · record
5. [5]
   R. W. Whatmore. Pyroelectric devices and materials (1986)

   Reports on Progress in Physics 49, 1335 · doi:10.1088/0034-4885/49/12/002 · crossref ✓ 2026-09-19 · record
6. [6]
   C. R. Bowen et al.. Pyroelectric materials and devices for energy harvesting applications (2014)

   Energy & Environmental Science 7, 3836–3856 · doi:10.1039/C4EE01759E · crossref ✓ 2026-09-19 · record
7. [7]
   H. B. Radousky, H. Liang. Energy harvesting: an integrated view of materials, devices and applications (2012)

   Nanotechnology 23, 502001 · doi:10.1088/0957-4484/23/50/502001 · crossref ✓ 2026-09-19 · record