Size induced change-over from first to second order magnetic phase transition in La0.67Ca0.33MnO3 nanoparticles

Details Size induced change-over from first to second order magnetic phase transition in La0.67Ca0.33MnO3 nanoparticles Size induced change-over from first to second order magnetic phase transition in La0.67Ca0.33MnO3 nanoparticles

2008-04-23

arxiv.org/abs/0804.3641v1

Physics

Condensed Matter

Strongly Correlated Electrons

6 pages, 6 figures

Scientific paper

In this report we show that in the perovskite manganite La_{1-x}Ca_{x}MnO_3 for a fixed x \approx 0.33, the magnetic transition changes over from first order to second order on reducing the particle size to nearly few tens of a nanometer. The change-over is brought about only by reducing the size and with no change in the stoichiometry. The size reduction to an average size of about 15 nm retains the ferromagnetic state albeit with somewhat smaller saturation magnetization and the ferromagnetic transition temperature T_{C} is suppressed by a small amount (4%). The magnetization of the nanoparticles near T_{C} follow the scaling equation $M/|\epsilon|^\beta = f_\pm(H/|\epsilon|^{\gamma+\beta})$, where, $\epsilon = |T-T_C|/T_C$. The critical exponents, associated with the transition have been obtained from modified Arrott plots and they are found to be $\beta=0.47\pm 0.01$ and $\gamma=1.06\pm 0.03$. From a plot of M vs H at T_{C} we find the exponent $\delta=3.10 \pm 0.13$. All the exponents are close to the mean field values. The change-over of the order of the transition has been attributed to a lowering of the value of the derivative dT_{C}/dP due to an increased pressure in the nanoparticles arising due to size reduction. This effect acts in tandem with the rounding off effect due to random strain in the nanoparticles.

Affiliated with

Also associated with

No associations

Rating

Size induced change-over from first to second order magnetic phase transition in La0.67Ca0.33MnO3 nanoparticles does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Size induced change-over from first to second order magnetic phase transition in La0.67Ca0.33MnO3 nanoparticles, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Size induced change-over from first to second order magnetic phase transition in La0.67Ca0.33MnO3 nanoparticles will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-104577