[19p-P1-1~74] 10 スピントロニクス・マグネティクス（ポスター）

▲ [19p-P1-44] Ferromagnetic resonance study on Y-type hexaferrite Ba_0.5Sr_1.5Zn₂Fe₁₂O₂₂

〇(P)Cho Jaehun^1,2、Kim Nam-Hui²、Yoon Jungbum²、Song Kimyung²、Hur Namjung²、You Chun-Yeol²、Park Seung-Young³、Jung Myung-Hwa⁴、Hiraoka Yuji¹、Kimura Tsuyoshi¹、Nawaoka Kohei¹、Miwa Shinji¹、Suzuki Yoshishige¹ (1.Osaka Univ., Japan、2.Inha Univ., Korea、3.KBSI, Korea、4.Sogang Univ., Korea)

キーワード：Y-type hexaferrite,Ferromagnetic resonance, FMR,Ba0.5Sr1.5Zn2Fe12O22

Hexaferrites have attracted considerable interests as the variety of structural and chemical variations which enable a large degree of flexibility in their magnetic phases. It has been reported Ba_0.5Sr_1.5Zn₂Fe₁₂O₂₂ shows magnetically induced ferroelectricity and a magnetoelectric effect related to modifications of a spiral magnetic structure by applying a magnetic field.¹ The magnetic structure in the ferroelectric phase is stabilized only in the intermediate magnetic field regime (intermediate-III phase) and does not seem to essentially differ from the nonpolar phase in the lower magnetic field (intermediate-II phase). Observation of any subtle difference in the intermediate magnetic phases can be invaluable in understanding microscopic mechanism of the magnetically induced ferroelectricity in Ba_0.5Sr_1.5Zn₂Fe₁₂O₂₂.
In this study, single crystals of Ba_0.5Sr_1.5Zn₂Fe₁₂O₂₂ are grown from Na₂O-Fe₂O₃ flux and we employed vector network analyzer ferromagnetic resonance (VNA-FMR) to investigate the magnetic phase diagram of Ba_0.5Sr_1.5Zn₂Fe₁₂O₂₂. Fig. 1(a) shows FMR spectra with increasing field at 100K. By employing the VNA-FMR analysis, we found new magnetic dynamic phases within the intermediate-II state. (We refer to the phases as intermediate-IIA and -IIB phases.) In the two phases, distinguishable VNA-FMR spectra were obtained.
This work was supported by ImPACT Program of Council for Science, Technology and Innovation.

¹ T. Kimura et al., Phys. Rev. Let. 94. 137201 (2005).