Nature of magnetic phase transitions and spin-driven ferroelectricity in BaHoFe⁢O4./sub

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378271%3A_____%2F25%3A00638741" target="_blank" >RIV/68378271:_____/25:00638741 - isvavai.cz</a>

Výsledek na webu

<a href="https://hdl.handle.net/11104/0369334" target="_blank" >https://hdl.handle.net/11104/0369334</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/xz8c-3fp3" target="_blank" >10.1103/xz8c-3fp3</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Nature of magnetic phase transitions and spin-driven ferroelectricity in BaHoFe⁢O4./sub

Popis výsledku v původním jazyce

BaHoFeO4 is an emergent multiferroic material that exhibits unique magnetic-field (H)-induced ferroelectric behavior. However, the origin of this effect has remained elusive, due to the role of complex magnetic interactions in driving the system's behavior. To shed light on this, we investigated the magnetic structures of the material using neutron powder diffraction, as well as their magnetic-field-induced evolutions through a combination of complementary techniques, including magnetic measurements, Mössbauer spectroscopy, and terahertz time-domain spectroscopy. The orthorhombic crystal structure of the compound, characterized by the structural interconnection between two-dimensional Fe chains and Ho chains, remains stable upon cooling to 3 K. Below TN1 ≈ 50 K, Fe³⁺ spins form a collinear incommensurate spin-density-wave antiferromagnetic order with a magnetic propagation vector k1 = (0, 0, 0.329), and the magnetic moments align along the b-axis. Upon further cooling, the enhancement of the 3d-4f exchange coupling induces long-range order in the Ho sublattice below 25 K, transforming the magnetic structure into a noncollinear commensurate antiferromagnetic order with k2 = (0.5, 0, 0.5), with all Fe and Ho moments lying in the ac plane. As the temperature decreases further, strengthening of the 4f-4f interactions leads to the emergence of a new commensurate antiferromagnetic order with a magnetic propagation vector k3 = (0, 0, 0.5) at 3 K, coexisting with the antiferromagnetic structure associated with k2. Similar to the incommensurate spin-density-wave structure, the Ho and Fe spins in the k₃ phase are oriented along the b-axis, with their magnetic moments modulated along the c-axis. The spin configuration of the Ho rings is highly sensitive to temperature and magnetic field, in contrast to the more robust spin configuration of the Fe rings. We attribute the H-induced magnetic and ferroelectric transitions in BaHoFeO4 to the H-induced modifications in the Ho sublattice. Two metamagnetic phase transitions occur at H1 ≈ 1 T and H2 ≈ 2 T, associated with a spin-flop transition of the Ho magnetic sublattice. The H-induced canted magnetic configuration in the Ho rings above H1 drives the H-induced ferroelectricity in BaHoFeO4. This is subsequently suppressed by the growth of a higher-field paraelectric antiferromagnetic phase, characterized by a fully ferromagnetic arrangement of the Ho chains above H2. Our study provides important insights into the origins of the metamagnetic phase transitions and the associated magnetoelectric effects.

Název v anglickém jazyce

Nature of magnetic phase transitions and spin-driven ferroelectricity in BaHoFe⁢O4./sub

Popis výsledku anglicky

BaHoFeO4 is an emergent multiferroic material that exhibits unique magnetic-field (H)-induced ferroelectric behavior. However, the origin of this effect has remained elusive, due to the role of complex magnetic interactions in driving the system's behavior. To shed light on this, we investigated the magnetic structures of the material using neutron powder diffraction, as well as their magnetic-field-induced evolutions through a combination of complementary techniques, including magnetic measurements, Mössbauer spectroscopy, and terahertz time-domain spectroscopy. The orthorhombic crystal structure of the compound, characterized by the structural interconnection between two-dimensional Fe chains and Ho chains, remains stable upon cooling to 3 K. Below TN1 ≈ 50 K, Fe³⁺ spins form a collinear incommensurate spin-density-wave antiferromagnetic order with a magnetic propagation vector k1 = (0, 0, 0.329), and the magnetic moments align along the b-axis. Upon further cooling, the enhancement of the 3d-4f exchange coupling induces long-range order in the Ho sublattice below 25 K, transforming the magnetic structure into a noncollinear commensurate antiferromagnetic order with k2 = (0.5, 0, 0.5), with all Fe and Ho moments lying in the ac plane. As the temperature decreases further, strengthening of the 4f-4f interactions leads to the emergence of a new commensurate antiferromagnetic order with a magnetic propagation vector k3 = (0, 0, 0.5) at 3 K, coexisting with the antiferromagnetic structure associated with k2. Similar to the incommensurate spin-density-wave structure, the Ho and Fe spins in the k₃ phase are oriented along the b-axis, with their magnetic moments modulated along the c-axis. The spin configuration of the Ho rings is highly sensitive to temperature and magnetic field, in contrast to the more robust spin configuration of the Fe rings. We attribute the H-induced magnetic and ferroelectric transitions in BaHoFeO4 to the H-induced modifications in the Ho sublattice. Two metamagnetic phase transitions occur at H1 ≈ 1 T and H2 ≈ 2 T, associated with a spin-flop transition of the Ho magnetic sublattice. The H-induced canted magnetic configuration in the Ho rings above H1 drives the H-induced ferroelectricity in BaHoFeO4. This is subsequently suppressed by the growth of a higher-field paraelectric antiferromagnetic phase, characterized by a fully ferromagnetic arrangement of the Ho chains above H2. Our study provides important insights into the origins of the metamagnetic phase transitions and the associated magnetoelectric effects.

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

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

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

5

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

15

Strana od-do

054437

Kód UT WoS článku

001553595000001

EID výsledku v databázi Scopus

2-s2.0-105020907667