Large Magneto-piezoelectric Effect in EuMnBi2 Single Crystal at Low Temperatures

Abstract

Magneto-piezoelectric effect (MPE) refers to generation of strain in response to electric currents in magnetic metals which lack both time-reversal and space-inversion symmetries. A recent experimental paper demonstrated the Mpe in the antiferromagnetic metal euMnBi 2 at 77 K, but the limited temperature range of the Mpe measurement hampered detailed discussion on the Mpe. Here we extend the measurement temperature range down to liquid He temperature, and studied the dependences of the Mpe on the laser position, frequency and amplitude of electric currents, and temperature in the very low temperature range. We show that the Mpe signal is enhanced at low temperatures and reaches a maximum magnitude in the antiferromagnetically ordered states of both Eu and Mn ions. An effective piezoelectric coefficient for the MPE at 4.5 K is estimated to be as large as 3500 pC/N, which is much larger than piezoelectric coefficients of typical piezoelectric ceramics, although the magnitude of real Mpe displacements should be limited due to strong Joule heating at high electric currents. the present results may open up a new strategy to realize new lead-free piezoelectric materials.

Superconducting piezoelectric effect

“…The MPE coefficients are nearly proportional to the magnetic field and vanish at zero magnetic field. This linear relation indicates the controllability of the MPE, which is different from the previous theories [16,21] and experiments [17][18][19]. Previous studies worked on the parity-breaking antiferromagnet, which we can control by domain switching using the electric current [22][23][24][25].…”

“…Experiments have been performed for the latter with antiferromagnetic metals EuMnBi 2 and CaMn 2 Bi 2 , and the MPE has been actually observed [17,18]. Remarkably, the latest experimental result reveals that the MPE response becomes larger with the higher conductivity [19]. This is consistent with the MPE which occurs only in metals [16], while it contrasts with the fact that the conventional PE is suppressed by the higher conductivity.…”

“…2. Because the SCPE and MPE coefficients are defined on an equal footing and the MPE was observed [17][18][19], Fig. 6 reveals the nonnegligible coupling of the supercurrent and lattice distortion.…”

Nonlinear electric transport in odd-parity magnetic multipole systems: Application to Mn-based compounds

“…In BaMn 2 As 2 and related materials, the momentumspace polarization can be induced by the nematicity. We can understand this by the discussion of the magnetopiezoelectric effect [24,[54][55][56][57]. A magnetopiezoelectric effect means that the planer (electronic) nematicity is induced by the out-of-plane electric current.…”

Systematic analysis method for nonlinear response tensors

“…Less ordinary responses have been paid much attention recently, especially in cooperation with antiferromagnetism with peculiar magnetic ordering patterns. For example, the anomalous Hall effect (AHE) [1][2][3], Kerr effect [4][5][6][7], Nernst effect [8][9][10][11], magnetoelectric effect [12][13][14][15][16][17][18][19], magnetopiezoelectric effect [20][21][22], and nonreciprocal transports in multiferroic materials [23] have been extensively investigated. In particular, the nontrivial AHE under the collinear [24][25][26][27][28] and non-collinear [29][30][31][32][33][34] antiferromagnetic (AFM) ordering has been studied multidirectionally.…”