Magnetocaloric effect in multiferroic Y-type hexaferrite Ba0.5Sr1.5Zn2(Fe0.92Al0.08)12O22

Abstract

Magnetocaloric effect is investigated in multiferroic Ba0.5Sr1.5Zn2(Fe0.92Al0.08)12O22 ceramic with Y-type hexagonal system. Three magnetic transitions, from alternating longitudinal conical to mixed conical at ∼240 K, to ferrimagnetic at ∼297 K, further to paramagnetic at ∼702 K, are unambiguously determined. Furthermore, obvious MCE is shown, and the maximum values of the magnetic entropy change and relative cooling power are evaluated to be 1.53 JKg−1K−1 and 280 JKg−1 for a field change of 7 T, respectively. In addition, inverse MCE is also observed, which might be associated with the first-order magnetic phase transition between two incommensurate longitudinal conical phases.

Broadband transverse susceptibility in multiferroic Y-type hexaferrite Ba0.5Sr1.5Zn2Fe12O22

“…According to previous studies [7,14], the BSZFO system undergoes an antiferromagnetic transition at 337 K after a sudden decrease of magnetization over 315 K, that is connected with a metamagnetic spin transition [18]. This transition is related with the sudden change of the angle from 134º to 180º (i.e.…”

“…the collinear planar structure) [13]. It is also known that these transition temperatures can be reduced up to 19 K due to sintering conditions [18,34]. In particular, the results reported by Kamba et al [34] with magnetization measurements attribute to the cooling stage in sample fabrication this temperature variation.…”

“…In the last years several compounds belonging to this structural phase have been identified as good candidates regarding their magnetoelectric properties, namely Ba 2 Mg 2 Fe 12 O 22 [8][9][10], Ba 0.5 Sr 1.5 Co 2 Fe 12 O 22 (BSFCO) [11,12], Ba 0.5 Sr 1.5 Zn 2 Fe 12 O 22 (BSZFO) [13,14] and Al substituted variants Ba 0.5 Sr 1.5 Co 2 (FeAl) 12 O 22 (BSCFAO) [15][16][17] and Ba 0.5 Sr 1.5 Zn 2 (FeAl) 12 O 22 . (BSZFAO) [18,19].…”

Laser Boron Fusion Reactor With Picosecond Petawatt Block Ignition

“…The condition of higher densities for explaining the blue shift caused complications for the PIC calculations which were mastered not before [33][34] [35]. For a completion or understanding of these conditions, PIC computations were performed for targets with densities close to the critical value where the optical constants are considerably deviating from the vacuum values [33] [34].…”

Single-Crystal Growth and Room-Temperature Magnetocaloric Effect of X-Type Hexaferrite Sr2Co2Fe28O46

“…Ba can be partially or fully substituted by Sr . Recently, magnetocaloric effect (MCE) was identified in some hexaferrites, such as M-type BaFe 12‑ x Co x Ti x O 19 , W-type BaCo 0.62 Zn 1.38 Fe 16 O 27 , and Y-type Ba 0.3 Sr 1.7 Co 2 Fe 12 O 22 and Ba 0.5 Sr 1.5 Zn 2 Fe 12 O 22 -related hexaferrites. − In addition, the magnetoelectric (ME) coupling has been also reported in Y-, M-, W-, U-, and Z-type hexaferrites with special conical magnetic structure except the X-type analog. − Considering the similar structural features of different hexaferrites, it is natural to predict the X-type hexaferrites being the right candidates for ME materials. However, the high-quality samples of X-type hexaferrites are difficult to prepare, especially a single crystal with high quality and large size.…”