A comparative study of the structural, optical, magnetic and magnetocaloric properties of HoCrO3 and HoCr0.85Mn0.15O3 orthochromites

authors	Kanwar, K; Coondoo, I; Anas, M; Malik, VK; Kumar, P; Kumar, S; Kulriya, PK; Kaushik, SD; Panwar, N
nationality	International
journal	CERAMICS INTERNATIONAL
author keywords	Rare-earth orthochromites; Structural distortion; Optical study; Magnetocaloric effect
abstract	In the present study, the physical properties including structural, optical and magnetic of HoCr1-xMnxO3 (x = 0, 0.15) have been thoroughly investigated and compared. A detailed structural analysis of the compounds provided a way to correlate the optical and magnetic properties with the change in Cr-site ionic radius, tilt angles and distortion in CrO6 octahedra due to Mn substitution. Further, the shift in the Raman phonon modes was associated with the increased structural distortion owing to Mn substitution in HoCrO3 compound. The variation in the Urbach energy values, measured from the diffuse reflectance spectroscopy, was found to be closely related to the octahedral distortion. The optical band gap reduced from 3.22 eV to 2.01 eV after Mn substitution. Other optical parameters such as skin depth, refractive index, extinction coefficient and optical conductivity were also perceived to vary noticeably in the substituted compound. The overall structural distortion with Mn substitution resulted in the decrease of antiferromagnetic transition temperature of the pristine compound. The strong magnetic entropy change was observed at low temperatures in pure HoCrO3 compound and its value was enhanced on Mn substitution. Therefore, the present work provides a convenient method to tune the multifunctional properties of HoCrO3 compound, which has practical applications such as photocatalyst and low-temperature magnetic refrigerant.
publisher	ELSEVIER SCI LTD
issn	0272-8842
isbn	1873-3956
year published	2021
volume	47
issue	6
beginning page	7386
ending page	7397
digital object identifier (doi)	10.1016/j.ceramint.2020.09.245
web of science category	12
subject category	Materials Science, Ceramics
unique article identifier	WOS:000621495500004