PHYSICAL REVIEW MATERIALS 4, 044407 (2020) Room-temperature magnetization reversal and magnetocaloric switching in Fe substituted GdMnO 3 Arnab Pal, 1 , * Manu Mohan, 1 Adyam Venimadhav, 2 and Pattukkannu Murugavel 1 , † 1 Department of Physics, Indian Institute of Technology Madras, Chennai 600036, India 2 Cryogenic Engineering Centre, Indian Institute of Technology Kharagpur, Kharagpur 721302, India (Received 7 November 2019; revised manuscript received 13 February 2020; accepted 27 March 2020; published 24 April 2020) Room-temperature tunable bipolar magnetization switching and magnetically switchable magnetocaloric phenomena having numerous application potentials are reported in GdMn 1−x Fe x O 3 (x = 0.55 and 0.60) polycrystalline samples. Substitution of Fe in antiferromagnetic GdMnO 3 induces a first-order spin-reorientation transition (T SR ), which along with antiferromagnetic ordering transition (T N ) gives rise to anomalies in dielectric spectra, a signature of magnetodielectric effect. Temperature-dependent Raman spectra confirm the spin-phonon coupling which could be the origin of the magnetodielectric effect in the system. Notably, low-field magnetically tunable magnetization reversal is found to appear between T SR and T N in these compounds owing to the competition between single-ion magnetic anisotropy and antisymmetric Dzyaloshinsky-Moriya interaction. Additionally, the GdMn 0.40 Fe 0.60 O 3 sample reveals the coexistence of magnetically switchable conventional and inverse magnetocaloric effect at 250 and 310 K. The tailoring of these coexisting room-temperature magnetization reversal and magnetocaloric phenomena in a single-phase system suggests a route to design the material suitable for potential applications in electromagnetic and memory devices. DOI: 10.1103/PhysRevMaterials.4.044407 I. INTRODUCTION Magnetodielectric materials are gaining importance due to the coupling between their dielectric and magnetic orders in same phase which is rare in nature [1–6]. Such systems can be either ferroelectric [7–10] or nonferroelectric [11–13], de- pending on their polar state. Even in nonferroelectric systems, the observed dielectric anomalies around magnetic transition temperatures can represent the magnetodielectric (MD) ef- fect [14,15]. However, irrespective of their polar state, these systems are attractive to research both in the fundamental and application point of view [2,3,16,17]. On the other hand, observation of magnetization reversal (negative magnetiza- tion) without reversing the direction of magnetic field in a magnetic material is considered as a noteworthy phenomenon in magnetism [18–37]. This phenomenon was first predicted by Néel in certain ferrimagnetic materials such as spinel oxides having different magnetic sublattices [38]. The dif- ferent temperature dependences in antiferromagnetic (AFM) exchange interactions between these sublattices yield a net zero magnetization at a characteristic temperature called com- pensation temperature below which a magnetization reversal occurs due to the domination of a particular sublattice [38,39]. Since then, this phenomenon was widely studied in various systems such as lithium chromium ferrite, orthovanadates, * Present address: Materials Genome Institute, Shanghai University, Shanghai 200444, China. † muruga@iitm.ac.in garnets, molecular magnets, hexacyanides, and intermetallics with distinctly different origin in each system [18–23]. Recently, the magnetization reversal studies have been extended to rare-earth based oxides such as orthoferrites, orthochromites, manganites, and ruthenites with the mixed A- and B-site perovskite (ABO 3 ) and double-perovskite (A 2 BB ′ O 6 ) structures [24–37]. It is primarily considered to be arisen from the competition between different magnetic interactions appearing at A- and B- sites. However, most of these systems show low compensation temperature, which restricts their application potential. Hence, designing the ma- terials exhibiting magnetization reversal near room tempera- ture is desirable to realize this phenomenon towards practical applications. YFe 0.5 Cr 0.5 O 3 and high-pressure synthesis of BiFe 0.5 Mn 0.5 O 3 are reported to serve this purpose to some extent with relatively high compensation temperatures at 248 and 208 K, respectively [31,40]. Although these works show the way of increasing compensation temperature, the ob- served values are far below room temperature. Additionally, designing the materials with high compensation temperature is gaining importance due to the fact that the conventional and inverse magnetocaloric effect (MCE) are reported near com- pensation temperature in few systems [21,31,33,37]. Hence- forth, it is important to propose a material showing unusual room-temperature magnetization reversal and MCE properties for practical applications. In this article, the single-phase perovskite GdMn 1−x Fe x O 3 (x = 0.55 and 0.60) system is chosen for the structural, dielec- tric, magnetic, and MCE studies. The two parent compounds of this system, namely GdMnO 3 and GdFeO 3 crystallize in orthorhombic structure with different magnetic transition 2475-9953/2020/4(4)/044407(8) 044407-1 ©2020 American Physical Society