A. Tikhanovskii, V. Yu. Ivanov, A. Kuzmenko, E. Constable, A. Pimenov, A. Mukhin
{"title":"The effect of local distortions on magnetic and magnetoelectric properties of paramagnetic Pr3Ga5SiO14 langasite","authors":"A. Tikhanovskii, V. Yu. Ivanov, A. Kuzmenko, E. Constable, A. Pimenov, A. Mukhin","doi":"arxiv-2409.07897","DOIUrl":null,"url":null,"abstract":"Magnetic field-induced electric polarization has been observed in trigonal\nnon-centrosymmetric paramagnetic Pr3Ga5SiO14 langasite. We detected quadratic\nelectric polarization along the a-axis in the basal ab plane for various\nmagnetic-field orientations. Electric polarization along the c-axis is only\nevident starting from the fourth power of magnetic field, in accordance with\nthe trigonal symmetry. The magnetic properties of Pr3Ga5SiO14 primarily stem\nfrom the local anisotropic magnetic moment of the two lowest Pr3+ singlets\n(quasi-doublet) in the crystal electric field. The random distribution of Ga/Si\nin the 2d positions leads to a local distortion of C2 symmetry and to a\nsplitting distribution of the quasi-doublet. By considering the interactions of\nlocal moments among different Pr3+ positions within a phenomenological approach\nfor the allowed magnetoelectric coupling, we derive the electric polarization\nin terms of symmetry-allowed combinations of local magnetic susceptibilities\nand field components. The magnetic field dependence of electric polarization in\nthe basal plane, P_{a,b*}, is mainly determined by the accumulation of\neffective local susceptibilities, exhibiting similar behavior in low fields,\nwhile polarization along the c-axis, P_c, arises from the non-equivalence of\nlocal effective magnetic susceptibilities in different Pr3+ positions. Our\nfindings suggest that the temperature dependencies of magnetic and\nmagnetoelectric susceptibilities are highly sensitive to the distribution of\nthe quasi-doublet splitting, which reflects the local symmetry breaking.","PeriodicalId":501234,"journal":{"name":"arXiv - PHYS - Materials Science","volume":null,"pages":null},"PeriodicalIF":0.0000,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv - PHYS - Materials Science","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/arxiv-2409.07897","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
Magnetic field-induced electric polarization has been observed in trigonal
non-centrosymmetric paramagnetic Pr3Ga5SiO14 langasite. We detected quadratic
electric polarization along the a-axis in the basal ab plane for various
magnetic-field orientations. Electric polarization along the c-axis is only
evident starting from the fourth power of magnetic field, in accordance with
the trigonal symmetry. The magnetic properties of Pr3Ga5SiO14 primarily stem
from the local anisotropic magnetic moment of the two lowest Pr3+ singlets
(quasi-doublet) in the crystal electric field. The random distribution of Ga/Si
in the 2d positions leads to a local distortion of C2 symmetry and to a
splitting distribution of the quasi-doublet. By considering the interactions of
local moments among different Pr3+ positions within a phenomenological approach
for the allowed magnetoelectric coupling, we derive the electric polarization
in terms of symmetry-allowed combinations of local magnetic susceptibilities
and field components. The magnetic field dependence of electric polarization in
the basal plane, P_{a,b*}, is mainly determined by the accumulation of
effective local susceptibilities, exhibiting similar behavior in low fields,
while polarization along the c-axis, P_c, arises from the non-equivalence of
local effective magnetic susceptibilities in different Pr3+ positions. Our
findings suggest that the temperature dependencies of magnetic and
magnetoelectric susceptibilities are highly sensitive to the distribution of
the quasi-doublet splitting, which reflects the local symmetry breaking.