Magnetic, transport, and electron magnetic resonance properties ofLa0.82Ca0.18MnO3single crystals

Measurements of electrical resistance, magnetization, ac magnetic susceptibility, and ferromagnetic resonance of ${\mathrm{La}}_{0.82}{\mathrm{Ca}}_{0.18}{\mathrm{MnO}}_3$ single crystal were carried out at temperatures below and above the Curie temperature, $T_C=180\mathrm{}\pm 1\mathrm{K}.$ A state of mixed ferromagnetic phases, metallic and insulating, is clearly evident from the measurements of magnetization, ac susceptibility, and electron magnetic resonance, below $T_C.$ The effect of applied hydrostatic pressure P and magnetic field H on the magnetic and the resistive properties were also investigated. It was found that the pressure enhances the magnetization, $T_C,$ and stabilizes the ferromagnetic metal-like phase. It is concluded that phase separation plays an important role in most magnetic and transport effects observed in ${\mathrm{La}}_{0.82}{\mathrm{Ca}}_{0.18}{\mathrm{MnO}}_3$ below and above $T_C.$