Near complete laser-induced modulation of the ferromagnetic-antiferromagnetic phase fraction in FeRh films

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216305%3A26620%2F26%3A0200644" target="_blank" >RIV/00216305:26620/26:0200644 - isvavai.cz</a>

Výsledek na webu

<a href="https://journals.aps.org/prb/abstract/10.1103/fytj-vy5c" target="_blank" >https://journals.aps.org/prb/abstract/10.1103/fytj-vy5c</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/fytj-vy5c" target="_blank" >10.1103/fytj-vy5c</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Near complete laser-induced modulation of the ferromagnetic-antiferromagnetic phase fraction in FeRh films

Popis výsledku v původním jazyce

With its huge entropy change and a strong interplay between magnetic order, structural and electrical properties, the first-order antiferromagnetic/ferromagnetic phase transition is a paradigmatic example of the multicaloric effect. The unraveling of the physics underlying the phase transition needs a better understanding of the thermal hysteresis of FeRh within the AF-FM phase coexistence region. In this work, we compare the effect of two very different types of thermal cycling on the hysteresis of the magnetic order: quasistatic heating, and cooling of the entire 195 nm thick film, and a f = 100 kHz modulated heating driven by a laser focused down to a spot of about 10 mu m2 at the film surface. Taking advantage of the reflectivity difference between both phases to probe optically their respective fraction, we show that whereas only temperature-driven reflectivity variations (dR/dT , thermoreflectance) are detected in the pure phases, a huge modulation of the phase-dependent reflectance at the driving frequency f is detected in the phase coexistence temperature range. This is quantitatively described as resulting from a substantial modulation of the FM fraction (up to 90%) with increasing laser power. A simplified rate-independent hysteresis model with return-point-memory (RPM), represented in terms of bistable units that undergo a temperature excursion corresponding to a given laser power, reproduces very well the optically measured FM phase modulation characteristics for a broad range of temperature excursions. This offers an insight into the leading role of quenched disorder in defining thermal hysteresis in FeRh under high excitation frequency, when the material is periodically driven out-of-equilibrium.

Název v anglickém jazyce

Near complete laser-induced modulation of the ferromagnetic-antiferromagnetic phase fraction in FeRh films

Popis výsledku anglicky

With its huge entropy change and a strong interplay between magnetic order, structural and electrical properties, the first-order antiferromagnetic/ferromagnetic phase transition is a paradigmatic example of the multicaloric effect. The unraveling of the physics underlying the phase transition needs a better understanding of the thermal hysteresis of FeRh within the AF-FM phase coexistence region. In this work, we compare the effect of two very different types of thermal cycling on the hysteresis of the magnetic order: quasistatic heating, and cooling of the entire 195 nm thick film, and a f = 100 kHz modulated heating driven by a laser focused down to a spot of about 10 mu m2 at the film surface. Taking advantage of the reflectivity difference between both phases to probe optically their respective fraction, we show that whereas only temperature-driven reflectivity variations (dR/dT , thermoreflectance) are detected in the pure phases, a huge modulation of the phase-dependent reflectance at the driving frequency f is detected in the phase coexistence temperature range. This is quantitatively described as resulting from a substantial modulation of the FM fraction (up to 90%) with increasing laser power. A simplified rate-independent hysteresis model with return-point-memory (RPM), represented in terms of bistable units that undergo a temperature excursion corresponding to a given laser power, reproduces very well the optically measured FM phase modulation characteristics for a broad range of temperature excursions. This offers an insight into the leading role of quenched disorder in defining thermal hysteresis in FeRh under high excitation frequency, when the material is periodically driven out-of-equilibrium.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

—

Návaznosti

—

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Physical Review B

ISSN

2469-9950

e-ISSN

2469-9969

Svazek periodika

112

Číslo periodika v rámci svazku

13

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

17

Strana od-do

—

Kód UT WoS článku

001596824000011

EID výsledku v databázi Scopus

2-s2.0-105020572509