# Rounding of a first-order magnetic phase transition in Ga doped La0.67Ca0.33MnO3 Source: [Rounding of a first-order magnetic phase transition in Ga doped La0.67Ca0.33MnO3]() Collection index: [llms.txt]() Data updated: 2025-10-23T14:57:13.366Z Authors: S. Roessler, U.K. Roessler, K. Nenkov, D. Eckert, S.M. Yusuf, K. Dorr, K.-H. Muller Published: 2004-07-19T16:44:20.000Z ## Abstract The effect of disorder on the critical properties of the ferromagnetic phase transition in colossal magnetoresistive manganite La0.67Ca0.33MnO3 has been studied by substituting Ga for Mn. It is found that, upon 10% Ga substitution, the peak in the specific heat at the Curie point T\_C changes drastically and appears as a small anomaly. Static magnetization data analyzed in the asymptotic critical region using modified Arrott plots and the Kouvel-Fisher method give values for the critical exponents beta=0.387(6), gamma=1.362(2), and delta=4.60(3). The results show that the first-order transition in La0.67Ca0.33MnO3 becomes continuous by Ga substitution. The critical properties of the rounded transition in La0.67Ca0.33Mn0.9Ga0.1O3 suggest that the magnetic subsystem in this mixed-valent perovskite is close to that of a conventional isotropic ferromagnet belonging to the Heisenberg universality class with short-range interactions. It is concluded that the first-order magnetic transition in pure La0.67Ca0.33MnO3 is induced by fluctuations from a competing mode, which couples to the magnetic subsystem. ## Recorded benchmark results A research result applies to its stated dataset, split, metric and evaluation configuration. Compare like-for-like settings, preserve the metric's unit and direction, and distinguish paper-reported results from independent reproduction. The best result recorded here is not a claim of exhaustive, current global coverage. ## Original sources and implementation [Original paper]() [PDF]()