Absence of mean-free-path effects in the current-perpendicular-to-plane magnetoresistance of magnetic multilayers

Eid, Khalid; Portner, David; Borchers, J. A.; Loloee, R.; Darwish, Muftah; Tsoi, Maxim; Slater, R. D.; O’Donovan, K. V.; Pratt, W. P.; Bass, J.

doi:10.1103/physrevb.65.054424

Cited by 47 publications

(79 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Here ρ is the resistivity of Pt, δ is the spin memory loss parameter 31,32 which describe the spin flip probability when an electron crosses the interface, and R * is an effective interface specific resistance. 7 We found that Equ.…”

Section: Resultsmentioning

confidence: 99%

Spin pumping and the inverse spin hall effect in single crystalline Fe/Pt heterostructure

et al. 2017

View full text Add to dashboard Cite

Spin pumping effect in single crystalline Fe/Pt bilayer has been systematically studied by the measurements of the microwave absorption spectrum and the inverse spin hall voltage detection. The gilbert damping constant of Fe first increases with Pt thickness and then saturates at tPt>1.5 nm. The spin diffusion length can be determined as 1.5±0.4 nm, and the spin mixing conductance is (3.4±0.4)×1019 m-2. The inverse spin hall voltage is quantitatively separated from the spin rectification effect through the measurement of the magnetization angular dependence, and the estimated spin hall angle of Pt is 0.048±0.015, in consistent with the values determined in polycrystalline Pt films.

show abstract

Section: Resultsmentioning

confidence: 99%

Spin pumping and the inverse spin hall effect in single crystalline Fe/Pt heterostructure

et al. 2017

View full text Add to dashboard Cite

show abstract

“…For F/N interfaces, we'll discuss in Section II.B2.b2.b what little is known. Interestingly, inclusion of modest spin-flipping at F/N interfaces does not greatly affect the CPP-MR of simple [F/N] N multilayers [16], where N is a significant number of bilayers. But it does affect the CPP-MR of symmetric exchange-biased spin-valves (EBSVs) [16], made up of only two equal-thickness F-layers, the magnetization of one pinned in a fixed direction by an adjacent antiferromagnet (AF), and the magnetization of the other free to reverse from parallel (P) to antiparallel (AP) to that of the first [17].…”

mentioning

confidence: 99%

Spin-diffusion lengths in metals and alloys, and spin-flipping at metal/metal interfaces: an experimentalist’s critical review

Bass¹,

Pratt²

2007

J. Phys.: Condens. Matter

544

585

View full text Add to dashboard Cite

In magnetoresistive (MR) studies of magnetic multilayers composed of combinations of ferromagnetic (F) and non-magnetic (N) metals, the magnetic moment (or related 'spin') of each conduction electron plays a crucial role, supplementary to that of its charge. While initial analyses of MR in such multilayers assumed that the direction of the spin of each electron stayed fixed as the electron transited the multilayer, we now know that this is true only in a certain limit. Generally, the spins 'flip' in a distance characteristic of the metal, its purity, and the temperature. They can also flip at F/N or N1/N2 interfaces. In this review we describe how to measure the lengths over which electron moments flip in pure metals and alloys, and the probability of spin-flipping at metallic interfaces. Spinflipping within metals is described by a spin-diffusion length, l M sf , where the metal M = F or N. Spin-diffusion lengths are the characteristic lengths in the current-perpendicular-to-plane (CPP) and lateral non-local (LNL) geometries that we focus upon in this review. In certain simple cases, l N sf sets the distance over which the CPP-MR and LNL-MR decrease as the N-layer thickness (CPP-MR) or N-film length (LNL) increases, and l F sf does the same for increase of the CPP-MR with increasing F-layer thickness. Spin-flipping at M1/M2 interfaces can be described by a parameter, δ M1/M2 , which determines the spin-flipping probability, P = 1 -exp(-δ). Increasing δ M1/M2 usually decreases the MR. We list measured values of these parameters and discuss the limitations on their determinations. OrganizationThis review is organized as follows. Section I provides a brief history and overview, defines the lengths of interest, briefly explains the physics underlying the spin-diffusion lengths that are the focus of the review, and discusses caveats on theoretical analysis and limitations on the measurements of the parameters of interest: the transport mean-free-path, λ t ; the spin-diffusion length in non-magnetic (N) metals or alloys, l N sf ; the spin-diffusion length in ferromagnetic (F) metals or alloys, l F sf ; and the interfacial spin-flip parameter, δ, where the spin-flipping probability is P = 1 -exp(-δ). Section II describes the different ways in which these parameters have been measured, and gives more specifics of their limitations. Section III contains four tables. Table I should be unique to each sample at 4.2K, but should be intrinsic in sufficiently high purity samples at 293K. Table III lists values of l F sf in ferromagnetic metals and alloys, mostly at 4.2K. Table IV lists values of δ N1/N2 for several N1/N2 metal pairs at 4.2K. Each table is preceded by some comments about the results. Section IV contains a brief summary and our conclusions. I. History, Overview, Definitions, and Caveats and Limitations. IA. History and Overview.The discovery in 1988 of Giant Magnetoresistance (GMR) in ferromagnetic/non-magnetic (F/N) metallic multilayers [1] [2] stimulated the growth of a new subfield of transport stud...

show abstract

“…As explained in [2], we don't trust most of these values. The only one in which we have some trust is our own δ Co/Cu = 0.25 ± 0.1 [4]. But the validity of even this value was unclear [2].…”

mentioning

confidence: 99%

“…Moreover, AΔR for simple [F/N] n multilayers is relatively insensitive to δ F/N . Absent a general technique for measuring δ F/N , values for a few F/N pairs have been inferred [4][5][6][7] from data not optimized for δ F/N . As explained in [2], we don't trust most of these values.…”

mentioning

confidence: 99%

See 1 more Smart Citation

A way to measure electron spin-flipping at ferromagnetic/nonmagnetic interfaces and application to Co/Cu

Dassonneville

Acharyya

Nguyen

et al. 2010

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

We describe a technique, using the current-perpendicular-to-plane (CPP) geometry, to measure the parameter δ F/N , characterizing flipping of electron spins at a ferromagnetic/non-magnetic (F/N) metallic interface. The technique involves measuring the CPP magnetoresistance of a sample containing a ferromagnetically coupled [F/N] n multilayer embedded within the 20 nm thick central Cu layer of a symmetric Py-based, double exchange-biased spin-valve. To focus on δ F/N , the F-and N-layers are made thin compared to their spin-diffusion lengths. We test the technique using F/N = Co/Cu. Analysing with no adjustable parameters, gives inconsistency with δ Co/Cu = 0, but consistency with our prior value of δ Co/Cu = 0.25 ± 0.1. Taking δ Co/Cu as adjustable gives δ Co/Cu = 33 . 0

show abstract

Absence of mean-free-path effects in the current-perpendicular-to-plane magnetoresistance of magnetic multilayers

Cited by 47 publications

References 29 publications

Spin pumping and the inverse spin hall effect in single crystalline Fe/Pt heterostructure

Spin pumping and the inverse spin hall effect in single crystalline Fe/Pt heterostructure

Spin-diffusion lengths in metals and alloys, and spin-flipping at metal/metal interfaces: an experimentalist’s critical review

A way to measure electron spin-flipping at ferromagnetic/nonmagnetic interfaces and application to Co/Cu

Contact Info

Product

Resources

About