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

Abstract

Noncollinear spin systems with magnetically induced ferroelectricity from changes in spiral magnetic ordering have attracted significant interest in recent research due to their remarkable magnetoelectric effects with promising applications. Single phase multiferroics are of great interest for these new multifunctional devices, being Y-type hexaferrites good candidates, and among them the ZnY compounds due to their ordered magnetic behaviour over room temperature. Polycrystalline Y type hexaferrites with composition Ba 0.5 Sr 1.5 Zn 2 Fe 2 O 22 (BSZFO) were sintered in 1050º C-1250º C temperature range.Transverse susceptibility measurements carried out on these BSZFO samples in the temperature range 80-350 K with DC fields up to ±5000 Oe reveal different behaviour depending on the sintering temperature.Sample sintered at 1250 ºC is qualitatively different, suggesting a mixed Y and Z phase like CoY hexaferrites. Sintering at lower temperatures produce single phase Y-type, but the transverse susceptibility behaviour of the sample sintered at 1150 ºC is shifted at temperatures 15 K higher. Regarding the DC field sweeps the observed behaviour is a peak that shifts to lower values with increasing temperature, and the samples corresponding to single Y phase exhibit several maxima and minima in the 250 K -330 K range at low DC applied field as a result of the magnetic field induced spin transitions in this compound.

Recent Progress in Hexagonal Ferrites Based Composites for Microwave Absorption

“…[110][111][112][113] The basic units of M-type ferrite and cubic spinal ferrites that retain a hexagonal crystal structure with magnetization parallel to the c-axis make up the crystal structure of Y-type. [70,114] The structure of y-type is said to be an alternate stacking of tetrahedral (T), and spinel (S) blocks parallel to the caxis with space group R-3m [115][116][117][118][119] and a = 5.9 Å and c = 43.5 Å as lattice parameters. [120,121] The formula for Y-type is A 2 M 2 Fe 12 O 22 , where A can be Ba or Sr and M is any divalent metal ion [122,123] and are attractive prospects for microwave device applications at high-frequency.…”

Persisting correlation between electrical transport and magnetic dynamics in M-type hexaferrites

“…Hexagonal ferrites (hexaferrites) are widely used and actively studied magnetic materials, which influenced both technological and scientific developments. Although known for more than half a century, they are still a fruitful topic in the research of physical phenomena such as multiferroicity and magnetoelectric effect [1,2,3]. Somewhat recently, it has been proposed that hexaferrites are hosts to the socalled quantum electric dipole liquid, a phase that could be described as the electric analog of the elusive quantum spin-liquid state [4], in which electric dipoles persist in a superposition configurations without long-range ordering down to the lowest of temperatures.…”