TY - JOUR
T1 - Second-order nonlinear optical and linear ultraviolet-visible absorption properties of the type-II multiferroic candidates RbFe(A O4)2 (A=Mo,Se, S)
AU - Owen, Rachel
AU - Drueke, Elizabeth
AU - Albunio, Charlotte
AU - Kaczmarek, Austin
AU - Jin, Wencan
AU - Obeysekera, Dimuthu
AU - Cheong, Sang Wook
AU - Yang, Junjie
AU - Cundiff, Steven
AU - Zhao, Liuyan
N1 - Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/2/5
Y1 - 2021/2/5
N2 - Motivated by the search for type-II multiferroics, we present a comprehensive optical study of a complex oxide family of type-II multiferroic candidates: RbFe(MoO4)2, RbFe(SeO4)2, and RbFe(SO4)2. We employ rotational-anisotropy second harmonic generation spectroscopy (RA SHG), a technique sensitive to point symmetries, to address discrepancies in literature-assigned point/space groups and to identify the correct crystal structures. At room temperature we find that our RA SHG patterns rotate away from the crystal axes in RbFe(AO4)2 (A=Se,S), which identifies the lack of mirror symmetry and in-plane two-fold rotational symmetry. Also, the SHG efficiency of RbFe(SeO4)2 is two orders of magnitude stronger than RbFe(AO4)2 (A=Mo,S), which suggests broken inversion symmetry. Additionally, we present temperature-dependent linear optical characterizations near the band edge of this family of materials using ultraviolet-visible absorption spectroscopy. Included is experimental evidence of the band gap energy and band gap transition type for this family. Subband gap absorption is also presented, which reveals prominent optical transitions, some with an unusual central energy temperature dependence. Furthermore, we find that by substituting the A site in RbFe(AO4)2 (A=Mo,Se,S), the aforementioned transitions are spectrally tunable. Finally, we discuss the potential origin and impact of these tunable transitions.
AB - Motivated by the search for type-II multiferroics, we present a comprehensive optical study of a complex oxide family of type-II multiferroic candidates: RbFe(MoO4)2, RbFe(SeO4)2, and RbFe(SO4)2. We employ rotational-anisotropy second harmonic generation spectroscopy (RA SHG), a technique sensitive to point symmetries, to address discrepancies in literature-assigned point/space groups and to identify the correct crystal structures. At room temperature we find that our RA SHG patterns rotate away from the crystal axes in RbFe(AO4)2 (A=Se,S), which identifies the lack of mirror symmetry and in-plane two-fold rotational symmetry. Also, the SHG efficiency of RbFe(SeO4)2 is two orders of magnitude stronger than RbFe(AO4)2 (A=Mo,S), which suggests broken inversion symmetry. Additionally, we present temperature-dependent linear optical characterizations near the band edge of this family of materials using ultraviolet-visible absorption spectroscopy. Included is experimental evidence of the band gap energy and band gap transition type for this family. Subband gap absorption is also presented, which reveals prominent optical transitions, some with an unusual central energy temperature dependence. Furthermore, we find that by substituting the A site in RbFe(AO4)2 (A=Mo,Se,S), the aforementioned transitions are spectrally tunable. Finally, we discuss the potential origin and impact of these tunable transitions.
UR - http://www.scopus.com/inward/record.url?scp=85100658548&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85100658548&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.103.054104
DO - 10.1103/PhysRevB.103.054104
M3 - Article
AN - SCOPUS:85100658548
SN - 2469-9950
VL - 103
JO - Physical Review B
JF - Physical Review B
IS - 5
M1 - 054104
ER -