Electrochemical growth and properties of LaMn_1−xCo_xO₃ (0 < x ≤ 1) single crystals

Abstract

Single crystals of LaMn 1-x Co x O 3 (0<x<1) with distorted perovskite structure have been obtained by the electrodeposition technique at anode from flux melt using Cs 2 MoO 4 -MoO 3 binary system as solvent. An investigation of magnetic and electrical properties of the obtained crystals as well as its comparison with those for ceramic samples of the same composition were carried out. A much weaker interplay between magnetic and electrical properties and a smaller ~8% magnetoresistance were found in the ternary oxide crystals slightly doped by Co on the verge of transition to ferromagnetic state in comparison to the data have been reported for LaMnO 3+δ single crystals.

New Member of the “112” Family, LaBaCo2O5.5: Synthesis, Structure, and Magnetism

“…During the past decade, the oxygen deficient ordered double perovskite cobaltates with the general formula LnBaCo 2 O 5.5 (Ln = lanthanoid or Y) have drawn significant interest due to their fascinating physical properties. − These 112 cobalt perovskites exhibit several magnetic transitions, paramagnetic (PM)/ferromagnetic (FM)/antiferromagnetic (AFM), in a wide temperature range. Moreover a semimetal/insulator transition is observed above room temperature.…”

Tailoring Oxygen Content on PrBaCo2O5+δ Layered Cobaltites

“…Although some previous reports on these materials are slightly older (e.g., refs 2 and 3), from the study of "Gd 0.5 Ba 0.5 CoO 3 " by Troyanchuck et al 4 reporting a metal insulator and two magnetic transitions, a vivid interest in these compounds has surged. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] Maignan et al 5 established that these cobaltites present two main structural features. The first one is that lanthanide and Ba ions do not form a solid solution at the A position of the perovskite structure but order in alternating (0 0 1) layers.…”

Electrochemical crystal growth and properties in Ln2O3–MnO–CoO (Ln=La, Ho) system

“…The ferromagnetic ordering of the LnCo 1Àx Mn x O 3+d (Ln ¼ La, Ho) samples has been explained on the basis of double exchange theory [8]. However, a strong insulating behavior of the samples in our case does not support this assumption [7]. It is probable that such ferromagnetic behavior results from dominant role of the positive superexchange interactions Mn 3+ -O-Mn 3+ , Mn 3+ -O-Mn 4+ , Co 2+ -O-Mn 4+ over the negative ones Co 2+ -O-Mn 3+ , Co 2+ -O-Co 2+ , Mn 4+ -O-Mn 4+ as has been noted earlier [9].…”

“…LaCo 1Àx Mn x O 3+d (0.5oxo1) single crystals grown by electrochemical flux technique reveal a ferromagnetic behavior at low temperatures, while a spin glass transition takes place for the crystals at higher cobalt contents [7]. In particular, the data measured on the single crystal show that LaMn 0.82 Co 0.18 O 3 is a fully polarized ferromagnet with the Curie temperature $170 K. Temperature dependences of zero field cooled and field cooled DC-susceptibility and isothermal magnetization in the basal plane of the HoCo 0.43 Mn 0.57 O 3+d single crystal are shown in Figs.…”

“…The crystals suitable for resistivity and susceptibility studies as well as Hall effect and spectroscopy measurements have been grown. Recently we successfully used their technique to grow large single crystals of LnMnO 3 (Ln ¼ La, Nd) and LaMn 1Àx Co x O 3 with a seed [6,7]. Here new results are presented on using a similar technique to grow single crystals of the pure rare earth and cobalt perovskites and the rare earth, manganese and cobalt ternary oxides, as well as some comparative data on magnetic properties of these crystals and preliminary results on crystal field excitation studies of a HoCoO 3 single crystal are collected.…”