Fabrication and magnetic response probed by RF transverse susceptibility in La0.67Ca0.33MnO3 nanowires

The temperature and magnetic field dependence of the radio-frequency (RF) transverse susceptibility (χT) of La0.67Ca0.33MnO3 crystalline nanowires has been studied using a very sensitive self-resonant tunnel-diode oscillator (TDO) technique. The nanowires were synthesized using porous templates of anodized alumina by chemical solution deposition technique, and the crystalline nature of the nanowires with the average diameter of 70 nm was confirmed by TEM, SAED, and HREM. RF transverse susceptibility experiments reveal the presence of a double-peak structure at T≤245 K (the Curie temperature) but a single peak at T>245 K. This distinguishes the low temperature ferromagnetic state from the high temperature paramagnetic state. The effective magnetic anisotropy field (HK), which corresponds to the peak location of χT, has been found to increase with decrease in temperature from the Curie temperature.