6533b821fe1ef96bd127b9bc

RESEARCH PRODUCT

Structural and Magnetic Dynamics in the Magnetic Shape Memory Alloy Ni$_2$MnGa

Gerhard JakobT. HuberS. GrübelPaul BeaudGerhard IngoldChristian DornesJennifer A. JohnsonAndrés FerrerH. J. ElmersS. O. MariagerT. EichhornSteven L. JohnsonAndrin CaviezelChristoph Quitmann

subject

QuenchingPhase transitionCondensed Matter - Materials ScienceMaterials scienceKerr effectCondensed matter physicsPhononDemagnetizing fieldNucleationMaterials Science (cond-mat.mtrl-sci)FOS: Physical sciencesCondensed Matter PhysicsElectronic Optical and Magnetic MaterialsCondensed Matter::Materials ScienceMagnetic shape-memory alloyMultiferroics

description

Magnetic shape memory Heusler alloys are multiferroics stabilized by the correlations between electronic, magnetic and structural order. To study these correlations we use time resolved x-ray diffraction and magneto-optical Kerr effect experiments to measure the laser induced dynamics in a Heusler alloy Ni$_2$MnGa film and reveal a set of timescales intrinsic to the system. We observe a coherent phonon which we identify as the amplitudon of the modulated structure and an ultrafast phase transition leading to a quenching of the incommensurate modulation within 300~fs with a recovery time of a few ps. The thermally driven martensitic transition to the high temperature cubic phase proceeds via nucleation within a few ps and domain growth limited by the speed of sound. The demagnetization time is 320~fs, which is comparable to the quenching of the structural modulation.

yearjournalcountryeditionlanguage
2014-05-26
10.1103/physrevb.90.161103http://arxiv.org/abs/1405.6534