Anisotropic magnetic properties of Pr1−xCaxMnO3

Abstract

We produced $c$-axis-oriented samples of Pr${}_{1\ensuremath{-}x}$Ca${}_{x}$MnO${}_{3}$ ($0.30\ensuremath{\le}x<0.50$) by applying a uniaxial pressure to quasisingle crystals with multiple domains at a high temperature. This reduced the number of domains in the crystals, allowing better investigation of their anisotropic magnetic properties. Below the N\'eel temperature, the magnetization curves can be classified into three Ca concentration ranges ($x=0.3$--0.33, $x=0.33$--0.37, and $x=0.4$--0.45). Our results indicate that the magnetic ground state strongly depends on the Ca concentration ($x$). For $x=0.30$--0.33, the ground state presents canted antiferromagnetic long-range order, presumably coexisting with ferromagnetic spin clusters. For $x=0.33$--0.37, the magnetic anisotropy undergoes steep changes near 25 K. These observations suggest the coexistence of ferromagnetic and antiferromagnetic spin clusters. Finally, for $x=0.4$--0.45, our measurements suggest the presence of small ferromagnetic spin clusters superimposed on the antiferromagnetic long-range order.