YBa₂Cu₃O_7-x

Value	Technique	Reference	Comments
Penetration depth (λ)
λa = 103±8 nm λb = 80±5 nm λc = 635±50 nm (for Ortho-I, Tc = 89 K, x = 6.995, T → 0 K)	ESR	Pereg-Barnea et al, PRB 69, 184513 (2004)	Also contains values for Tc = 56 K and 75 K underdoped samples, most useful table on bottom of page 10 and graph on top of page 11.
Δλa(T=77K) ≅ 94 nm Δλb(T=77K) ≅ 81 nm (Tc = 93.7 K, x = 6.993)	microwave surface impedance	Kamal et al, PRB 58, R8933 (1998)	λ(0) is not known, but λ(T) = λ(0) + Δλ. Δλa(T) and Δλb(T) are given for T = 1 K to Tc for three samples near optimal doping. (Exact values can be read from figs 1, 2, and 3.)
λab(0) = 118.5 ± 1.7 nm (London, hex) λab(0) = 111.5 ± 1.5 nm (GL, hex) λab(0) = 133.3 ± 2.4 nm (London, square) (x = 6.95, twinned)	μSR	Sonier et al, RMP 72, 769 (2000)	Explanation on page 793; μSR results are highly model-dependent. Figs 25, 26, 27, 28 show λab vs. temperature, twinning, disorder.
λab ~ 300 nm at 0.1Tc (Tc = 90.4 K)	scanning Hall probe	Oral et al, Supercond. Sci. Technol. 10, 17 (1997)	Imaged 5 vortices as a function of temperature, shows λ vs. T from 0.1Tc to 0.9Tc in Fig. 3.
λab = 320 nm at T = 6.7 K λab = 2020 nm at T = 78 K λab = 1690 nm at T = 80 K fit: λab(0) = 530 nm (Tc = 83.2 K)	magnetic force microscope	Lu et al, Physica C 371, 146 (2002)	λ shown vs. temperature in Fig. 4. measurement is pretty rough; assumptions about magnetic tip are not necessarily valid (the tip should be T-independent, but their fits indicate that it's not)
fit: λab(0) = 210 nm (Tc = 88 K, d = 100nm film)	kinetic inductance of film patterned into long meander line	Lee et al, APL 62, 2419 (1993)	λ shown vs. temperature in Fig. 4.
Coherence length (ξ)
ξab(0) = 1.41 ± 0.04 nm (x ≅ 0.9; Tc = 92 K)	4-wire resistivity Tc measurements for a series of films with different grain sizes	Gauzzi et al, Europhys. Lett. 51, 667 (2000)	Tc measured for a series of 40 nm thick epitaxial films; BCS temperature dependence of ξ is assumed.