Extremely strong anisotropy of out-of-phase component of AC magnetic susceptibility in hematite single crystals and its origin

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F22%3A00561314" target="_blank" >RIV/67985831:_____/22:00561314 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/22:10457216

Výsledek na webu

<a href="https://link.springer.com/article/10.1007/s11200-022-0829-2" target="_blank" >https://link.springer.com/article/10.1007/s11200-022-0829-2</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1007/s11200-022-0829-2" target="_blank" >10.1007/s11200-022-0829-2</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Extremely strong anisotropy of out-of-phase component of AC magnetic susceptibility in hematite single crystals and its origin

Popis výsledku v původním jazyce

So far unknown anisotropic properties of out-of-phase magnetic susceptibility (opMS) of hematite and their bearing on understanding the origin of hematite magnetism were investigated on example of four single crystals from Minas Gerais, Brazil. The research comprised measurement of directional variation of field-dependent and frequency-dependent opMS and testing whether the anisotropy of opMS can be represented by the second rank tensor. It was found that the opMS shows strong field dependence along basal plane and only weak field dependence along c-axis. As for the frequency dependence, it is virtually non-existent along the basal plane. Along the c-axis, the opMS is similar at frequencies 976 and 3904 Hz, while at 15616 Hz it is clearly higher. Consequently, opMS is dominantly due to weak field hysteresis. The minimum opMS directions are parallel to the c-axis, while the other two principal directions lie within basal plane. The degree of anisotropy is extremely high (ratio of maximum opMS to minimum opMS ≫100) and the anisotropy ellipsoid is very oblate. In stereographic diagrams, the opMS contours very roughly resemble the theoretical contours calculated from opMS tensor. However, the differences between measured and theoretical values in directional opMS are clearly higher than the measuring error and are distributed very non-homogeneously. This indicates that the second rank tensor is only very approximate representative of the spatial variation of the directional opMS of hematite single crystals. Earlier model of hematite magnetism assuming slightly scanted antiferromagnetism along the c-axis and strongly canted antiferromagnetism or even weak ferromagnetism along the basal plane is supported.

Název v anglickém jazyce

Extremely strong anisotropy of out-of-phase component of AC magnetic susceptibility in hematite single crystals and its origin

Popis výsledku anglicky

So far unknown anisotropic properties of out-of-phase magnetic susceptibility (opMS) of hematite and their bearing on understanding the origin of hematite magnetism were investigated on example of four single crystals from Minas Gerais, Brazil. The research comprised measurement of directional variation of field-dependent and frequency-dependent opMS and testing whether the anisotropy of opMS can be represented by the second rank tensor. It was found that the opMS shows strong field dependence along basal plane and only weak field dependence along c-axis. As for the frequency dependence, it is virtually non-existent along the basal plane. Along the c-axis, the opMS is similar at frequencies 976 and 3904 Hz, while at 15616 Hz it is clearly higher. Consequently, opMS is dominantly due to weak field hysteresis. The minimum opMS directions are parallel to the c-axis, while the other two principal directions lie within basal plane. The degree of anisotropy is extremely high (ratio of maximum opMS to minimum opMS ≫100) and the anisotropy ellipsoid is very oblate. In stereographic diagrams, the opMS contours very roughly resemble the theoretical contours calculated from opMS tensor. However, the differences between measured and theoretical values in directional opMS are clearly higher than the measuring error and are distributed very non-homogeneously. This indicates that the second rank tensor is only very approximate representative of the spatial variation of the directional opMS of hematite single crystals. Earlier model of hematite magnetism assuming slightly scanted antiferromagnetism along the c-axis and strongly canted antiferromagnetism or even weak ferromagnetism along the basal plane is supported.

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

<a href="/cs/project/GA19-17442S" target="_blank" >GA19-17442S: Anizotropie imaginární složky magnetické susceptibility jako nová metoda pro analýzu stavby hornin</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Studia geophysica et geodaetica

ISSN

0039-3169

e-ISSN

1573-1626

Svazek periodika

66

Číslo periodika v rámci svazku

3-4

Stát vydavatele periodika

CZ - Česká republika

Počet stran výsledku

19

Strana od-do

187-205

Kód UT WoS článku

000847600900001

EID výsledku v databázi Scopus

2-s2.0-85137077572