Enhanced structural, magnetodielectric, and multiferroic response in Fe and Co Co-doped Barium strontium titanate ceramics
A. Khan, Rahul Goel, Aayush Gupta, Harshit Tripathi, Naveen Kumar, Sumit Bhardwaj, Sanjeev Kumar, Indu Sharma, Rajesh Kumar, Pankaj Sharma, Sanjeev Kumar
Abstract
Abstract In this paper, the ambient temperature multiferroic effect resulting from the incorporation of transition metal ions (Fe 3+ and Co 2+ ) in lead-free BST [ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mrow> <mml:mi mathvariant="italic">Ba</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>0.7</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi mathvariant="italic">Sr</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>0.3</mml:mn> </mml:mrow> </mml:msub> <mml:mo stretchy="false">(</mml:mo> <mml:msub> <mml:mrow> <mml:mi mathvariant="italic">Fe</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>x</mml:mi> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi mathvariant="italic">Co</mml:mi> </mml:mrow> <mml:mrow> <mml:mi>x</mml:mi> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> <mml:mo stretchy="false">)</mml:mo> <mml:msub> <mml:mrow> <mml:mi mathvariant="italic">Ti</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> <mml:msub> <mml:mrow> <mml:mi>O</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>3</mml:mn> </mml:mrow> </mml:msub> <mml:mo>;</mml:mo> <mml:mi mathvariant="italic">x</mml:mi> <mml:mo>=</mml:mo> <mml:mn>0</mml:mn> <mml:mo>,</mml:mo> <mml:mn>0.0</mml:mn> <mml:mn>1</mml:mn> <mml:mo>,</mml:mo> <mml:mn>0.03</mml:mn> <mml:mo>,</mml:mo> <mml:mn>0.05</mml:mn> <mml:mo>,</mml:mo> <mml:mn>0.07</mml:mn> </mml:math> ] ceramics synthesized via the solid-state reaction (SSR) procedure has been thoroughly analyzed. The investigation consistently scrutinized the effects of augmenting transition metal co-doping on the structural, ferroelectric, dielectric, magnetic, and magnetodielectric characteristics. The x-ray diffraction (XRD) patterns for all ceramic compositions demonstrated the formation of a monophasic ( P4mm ) crystalline structure. The Raman analysis evidenced the presence of various modes, which are associated with the occurrence of the single-phase and provide strong corroboration for the x-ray diffraction observations. Scanning electron micrographs reveals that the inclusion of transition metal ions results in the diminution of grain size. The frequency-dependent dielectric characteristics were represented over the frequency range of 1 kHz to 1 MHz. The P-E hysteresis curves demonstrate a consistent reduction in the values of P s and P r , whereas, the M-H curve reveals the enhancement in magnetic properties with increased doping. The magnetodielectric analysis confirmed the interplay between the ferroelectric and ferromagnetic ordering. The BST-1CF sample exhibited the highest MC % value of 5.30% along with the magnetoelectric coupling coefficient ‘ γ ’ of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mo>−</mml:mo> <mml:mn>6.0</mml:mn> <mml:mn>1</mml:mn> <mml:mo>×</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width="1em"/> <mml:msup> <mml:mrow> <mml:mo stretchy="false">(</mml:mo> <mml:mi mathvariant="italic">memu</mml:mi> <mml:mo>/</mml:mo> <mml:mi>g</mml:mi> <mml:mo stretchy="false">)</mml:mo> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mo>,</mml:mo> </mml:math> making it a favorable entrant for the advancement of innovative non-volatile multiferroic memory gadgets.