Synthesis and Characterization of Chiral Magnetic Oxide: MnMoTeO6

The chiral materials lack mirror reflection symmetry in their crystal structures like right and left hands. Such materials often host unique non-collinear or topological magnetic textures such as magnetic skyrmions. If such magnetic textures are formed in insulating oxides with coupled electric and magnetic properties, then such magnetic structures can be controlled and manipulated using electric fields rather than electric current. With this motivation, we are synthesizing and characterizing chiral materials belonging to MMoTeO6 (M=Mn, Co, Fe, Cu, Ni) family. I will discuss about the phase formation and solid-state synthesis of MnTeMoO6 along with its structural, electrical and magnetic properties characterization

M-sigma relations across space and time

Feedback from active galactic nuclei (AGN) has long been invoked to explain the correlation between black hole mass and stellar velocity dispersion (M-{\sigma}) discovered in low redshift galaxies. We describe the time evolution of AGN in the M-{\sigma} plane based on our gap model (Garofalo, Evans & Sambruna 2010) for black hole accretion and jet formation illustrating a fundamental difference between jetted and non-jetted AGN. While the latter tend to evolve diagonally upward with black hole mass increasing along with stellar dispersion, we show that jetted AGN tend on average to move initially more upwards because their effect on velocity dispersion is weaker than for non-jetted AGN. But this initial phase is followed by a shift in the nature of the feedback, from positive to negative, a transition that is more dramatic on average in denser cluster environments. The feedback gets its kick from tilted jets which shut down star formation but increase velocity dispersion values. As this change in the nature of the feedback takes tens of million to hundreds of millions of years, jetted AGN triggered in mergers will evolve mostly upwards for up to order 10^8 years, followed by an extremely long phase in which low excitation progressively slows black hole growth but dramatically affects stellar dispersion. As a result, powerful jetted AGN evolve for most of their lives almost horizontally on the M-{\sigma} plane. The prediction is that strongest AGN feedback on stellar dispersion is a late universe phenomenon with M87 being a case in point. We show how jetted and non-jetted AGN parallel the Sersic and core-Sersic galaxy paths in the M-{\sigma} plane found by Sahu et al (2019)

Synthesis and Characterization of Chiral Magnetic Oxide: CoMoTeO_6

The materials that lack mirror reflection symmetry are called chiral materials. Such chiral materials often exhibit non-collinear or topological magnetic structures such as magnetic skyrmions. If such materials are insulating and magnetoelectric, then they can be ideal candidates to study the control and manipulation of magnetic textures using electric field rather than electric current. Motivated by this idea, we are studying the insulating chiral materials belonging MMoTeO6 (M=Co, Mn, Fe, Cu, Ni) family. I will talk about the solid-state synthesis CoTeMoO6 compound and its characterization using X-ray diffraction, magnetic measurements, and dielectric measurements