High magnetic field phase diagram in electron-doped manganites La0.4Ca0.6Mn1−yCryO3
نویسندگان
چکیده
We report the charge-order to ferromagnetic phase transition induced by pulsed high magnetic field and impurity doping effects in manganites La(0.4)Ca(0.6)(Mn(1-y)Cr(y))O3 (0 ≤ y ≤ 0.2). Significant charge-order suppression and ferromagnetic tendency upon the Cr(3+)-doping are evidenced, and three different ground states are identified, namely the charge-order state, the phase separated state, and the spin-glass like state. Phase diagram in the H-y plane at 4.2 K is determined by the high magnetic field study, in which the charge-order and ferromagnetic phase boundary is clearly figured out. The critical magnetic field for melting the charge-order phase of La(0.4)Ca(0.6)MnO3 is revealed to reach up to 46 T at 4.2 K. Interestingly, distinct responses of the three states to the high magnetic field are observed, indicating the special physics regarding the charge order melting process in each state. The mechanism of the doping induced charge-order suppression and ferromagnetism promotion can be understood by the competition between the antiferromagnetic interaction of Cr-Mn and local enhancement of electron hopping by Cr(3+).
منابع مشابه
Double exchange and orbital correlations in electron doped manganites
A double exchange model for degenerate eg orbitals with intraand inter-orbital interactions has been studied for the electron doped manganites A1−xBxMnO3 (x > 0.5). We show that such a model reproduces the observed phase diagram and orbital ordering in the intermediate bandwidth regime and the Jahn-Teller effect, considered to be crucial for the region x < 0.5, does not play a major role in thi...
متن کاملUnveiling new magnetic phases of undoped and doped manganites.
Novel ground-state spin structures in undoped and lightly doped manganites are investigated based on the orbital-degenerate double-exchange model, via mean-field and numerical techniques. In undoped manganites, a new antiferromagnetic (AFM) state, called the E-type phase, is found adjacent in parameter space to the A-type AFM phase. Its structure is in agreement with recent experimental results...
متن کاملFerromagnetism and Colossal Magnetoresistance from the Coexistence of Comparable Charge and Spin Density Orders
We report a complete multicomponent mean-field-theory for the coexistence and competition of charge ordering (CO), antiferromagnetic (AFM) and ferromagnetic (FM) spin ordering in the presence of a uniform magnetic field. Doping the AFM or CO state always generates a ferromagnetic component. Itinerant FM, AFM and CO, necessarily coexist and compete in a particle-hole asymmetric system. Melting o...
متن کاملCoexistence of long-ranged charge and orbital order and spin-glass state in single-layered manganites with weak quenched disorder
The relationship between orbital and spin degrees of freedom in the single-crystals of the hole-doped Pr1−xCa1+xMnO4, 0.3 ≤ x ≤ 0.7, has been investigated by means of acmagnetometry and charge transport. We show that in an intermediate underdoped region, with 0.35 ≤ x < 0.5, the “orbital-master spin-slave” relationship commonly observed in half-doped manganites does not take place. The long-ran...
متن کاملSurface Magnetic Phase Diagram of Tetragonal Manganites
To gain insights into the fundamental and characteristic features of the surface of doped manganites, we constructed a general magnetic phase diagram of La1−xSrxMnO3 (001) surfaces in the plane spanned by x and the bulk tetragonal distortion c/a, from the first-principles calculations. We found that the surfaces are quite different from the bulk in the sense that both the (La, Sr)O and MnO2 ter...
متن کامل