Contents lists available at ScienceDirect Physica B journal homepage: www.elsevier.com/locate/physb Observation of magnetization reversal and magnetocaloric effect in manganese modified EuCrO 3 orthochromites Surendra Kumar a , Indrani Coondoo b , M. Vasundhara c , Venkata S. Puli d , Neeraj Panwar a, ⁎ a Department of Physics, Central University of Rajasthan Bandarsindri, 305817 Ajmer, Rajasthan, India b Department of Physics & CICECO-Aveiro Institute of Materials, University of Aveiro, 39810-193 Aveiro, Portugal c Materials Science and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology, Industrial Estate, Trivandrum 695019, India d Department of Physics and Engineering Physics, Tulane University, New Orleans, LA 70118, USA ARTICLE INFO Keywords: 1. Chromites 2. Magnetization reversal 3. Spin reorientation 4. Magneto- caloric effect ABSTRACT We report here an investigation on the structural, magnetic and magnetocaloric properties of Mn doped EuCr 0.85 Mn 0.15 O 3 (ECMO) chromites synthesized via ceramic route. The compound crystallized into distorted orthorhombic structure with Pnma space group similar to that of its parent EuCrO 3 compound, as revealed from the refined of x-ray powder diffraction pattern, but with an increase in the lattice volume. Neel temperature, noticed at 162 K from the temperature variation of magnetization, smaller than that reported for pristine EuCrO 3 ; indicated the influence of Mn 3+ substitution in decreasing the antiferromagnetic ordering. Magnetization reversal evolved in the studied compound under lower field while such feature was absent in the undoped EuCrO 3 . Magnetocaloric effect was measured through the magnetic entropy change and relative cooling power. Near the spin reorientation transition temperature ~ 40 K, the magnetic entropy change was equal to 3.788 J kg -1 K -1 under 90 kOe field with 215.22 J kg -1 relative cooling power. The results have been understood in terms of the competition between Cr-rich clusters, Mn-rich clusters and local Mn-Cr ordered clusters and their different temperature dependency. 1. Introduction Rare-earth orthochromites with the general formula RCrO 3 (R =Y or trivalent rare-earth ion) have seen an unprecedented surge of worldwide research due to their peculiar magnetic properties. For example, below the Neel temperature (T N ); they exhibit canted anti- ferromagnetic (CAFM) behaviour, temperature induced magnetization reversal (TIMR), exchange bias (EB) and spin reorientation (SR) [1–6]. Their T N' s lie in the range between orthomanganites and orthoferrites. The orthochromites have also demonstrated ferroelectric polarization either induced by an external magnetic field (ME) or a spontaneous polarization as a consequence of internal magnetic fields induced by long-range magnetic ordering (thus exhibiting the multiferroic beha- viour) [7–12]. These properties make them suitable for spintronics, sensors, thermally assisted random access memory devices etc. [13– 16]. The orthochromites generally crystallize into distorted orthorhom- bic crystal structure with Pnma space group. The distortion from the ideal cubic perovskite structure is mainly in the dodecahedral rare- earth sites, resulting in the geometrical structure factor, t < 1. The Cr 3+ ions occupy the octahedral sites, which are less distorted by virtue of their rotation [17,18]. This causes slight canting of Cr 3+ ions, which should otherwise be antiparallel to each other; resulting in a weak ferromagnetic (WFM) behaviour below T N . The Cr 3+ ions produce an internal field at the rare-earth site, which is opposite to the magnetiza- tion of WFM component of Cr 3+ ions. The magnetic moment of the rare-earth ion (if it is magnetic) gets aligned by the internal field opposite to that of Cr 3+ ions. Above a particular temperature known as compensation or crossover temperature, magnetization of Cr 3+ ions dominates the rare-earth ion's magnetic moment and thereby resultant magnetization is positive. However, as the temperature lowers and passes the compensation temperature, the latter overcomes the former, resulting in negative magnetization or magnetization reversal (MR) [1,2,4,16]. Such interesting behaviour of MR is also reported upon partial replacement of Cr ions with the transition metal elements such as Mn and Fe [19–22]. Recently, a prominent MR behaviour is reported in 15% of Mn- substituted La-chromites [19] and Sm- chromites [20]. In addition to chromites, the MR effect has also been reported in several other systems like vanadates [23,24] and manga- nites [25,26]. In orthovanadates, the MR arises from the effects of antisymmetric Dzyloshinsky-Moriya (DM) interaction and magnetos- http://dx.doi.org/10.1016/j.physb.2017.05.050 Received 1 May 2017; Received in revised form 21 May 2017; Accepted 26 May 2017 ⁎ Corresponding author. E-mail addresses: neerajpanwar@curaj.ac.in, neeraj.panwar@gmail.com (N. Panwar). Physica B 519 (2017) 69–75 Available online 27 May 2017 0921-4526/ © 2017 Elsevier B.V. All rights reserved. MARK