Magnetotransport and magnetic properties of weak ferromagnetic semiconductors: Ca doped LaCrO3

Abstract

Transport, magnetic, specific heat, internal friction, and shear modulus in the charge ordered La 0. We report the magnetic and magnetotransport properties of Ca doped La 1−x Ca x CrO 3 ͑x = 0, 0.1, 0.2, and 0.3͒. Both the magnetic and transport properties are very sensitive to Ca substitution. The Néel temperature T N decreases substantially with increasing calcium doping concentration from 290 to 160 K. A weak ferromagnetic state with large coercive fields of up to 3 T is present for the Ca doped LaCrO 3 . The temperature dependence of the resistivity shows that all the Ca doped compounds are semiconducting and their resistivities decrease with increasing Ca for low doping levels. The resistivity curves show thermally activated behavior and a variable range hopping behavior at high temperatures. The magnetotransport measurements show a negative magnetoresistance. Furthermore, an anomalous peak was observed in the field dependence of magnetoresistance for the LCCO materials.

Large exchange bias effect in LaCr0.9Ru0.1O3

“…The Cr 3 þ (d 3 )-OCr 3 þ (d 3 ) AFM superexchange interaction is weaken with the doping of Ru ions. The canting of Cr spins or noncollinear FM in LCO is reported by several authors [10,20]. Beside this effect the existence of Cr 2 þ (d 4 ) and Ru 4 þ (d 4 ) introduce the double exchange (DE) FM interaction.…”

Structural characterization and electron density distribution studies of (La0.8Ca0.2)(Cr0.9−xCo0.1Mnx)O3

“…Studies on Ca doped LaCrO 3 showed that, with increasing calcium doping concentration, the Neel temperature T N decreases from 290 K to 160 K and a weak ferromagnetic state with large coercive fields is observed. This weak ferromagnetic moment is due to canting of the antiferromagnetically ordered Cr moments [35]. Tseggai et al [36] published an investigation on magnetic properties of Mn doped lanthanum chromites and showed that the Mn doped samples are antiferromagnetic at about 290 K, with canted magnetic moments yielding a ferromagnetic component.…”

Optical and magnetic properties of Gd1−x Sr x CrO3 (0 ⩽ x ⩽ 0.15)

“…Cr 3+ and Cr 4+ generally modifies electronic and magnetic properties of RCrO 3 compounds. It has been observed that divalent alkaline ions (such as Ca 2+ , Sr 2+ ) substitution for La 3+ in LaCrO 3 leads to the continuous decrease in T N with the increase of doping concentration [20][21][22]. The primary motivation of the present work is to tune the optical and magnetic properties of GdCrO 3 through introducing mixed valence state of Cr by cation replacement (alkaline Sr 2+ in place of RE Gd 3+ ions).…”